Experiment O1 page 1 of 13. Lab O1: Radioactivity and Counting Statistics

Size: px
Start display at page:

Download "Experiment O1 page 1 of 13. Lab O1: Radioactivity and Counting Statistics"

Transcription

1 Experiment O1 page 1 of 13 Lab O1: Radioactivity and Counting Statistics Radioactivity Radioactivity is a type of nuclear reaction, that is, a reaction which involve the breaking of nuclear bonds having energies of the order of 10 6 ev = 1MeV. The three most common types of radioactive emissions are: alpha rays: α rays or α particles are high-energy helium nuclei (2 protons + 2 neutrons), which are spontaneously emitted during the decay of some radioactive nuclei. α-rays are extremely damaging to biological tissue, but, fortunately, they have very little penetrating power. Several centimeters of air or a sheet of paper will stop α rays. The primary danger of α sources comes from inhalation or ingestion of trace sources so... no smoking or eating allowed when handling α sources. beta rays: β rays are high energy electrons emitted by nuclear reactions. β rays are generally less damaging than alpha rays but have greater penetrating power. A thick plate of Plexiglas or a thin sheet of metal are needed to stop β s. gamma rays: γ rays are high-energy photons, i.e. particles of electromagnetic radiation, like x- rays, but with higher energy, and more damaging, with much greater penetrating power. x-rays in medical applications are typically 20 kev in energy; gamma rays from nuclear reactions have energies of MeV. Several inches of lead are needed to significantly attenuate high-energy γ s We are continuously exposed to radioactivity from natural sources: mainly naturallyoccurring radioactive nuclei in cosmic rays and rocks. Cosmic rays are extremely high-energy charged particles, mostly hydrogen and helium nuclei, originating from outside our solar system, which strike the earth from all directions. The earth s atmosphere protects us from direct exposure to cosmic rays, but when they strike the upper atmosphere they precipitate a cascade of nuclear reactions whose decay products reach the ground. Here in Boulder, at an altitude of 1700 m (one mile), the natural radioactivity from cosmic rays is about twice as great as at sea level. Long-lived radioactive elements, mainly uranium and thorium, have been in the earth since its creation 4.8 billion years ago. These massive nuclei are unstable and spontaneously decay by fission, emitting α, β, and γ radiation, producing lighter elements (called daughter products), some of which are also radioactive. In the late 1940's to early 1960's, atmospheric testing of nuclear bombs released radioactive fission fragments into our environment, and some of these are still present, not having decayed yet. Among these is strontium-90, which is particularly dangerous because it is chemically similar to calcium and, when eaten or inhaled, is retained by the body and concentrates in bone tissue. One way to describe the strength of a radioactive source is to give its activity, which is the number of radioactive decay events per second. The curie (Ci) is a unit of activity equal to decays/sec; this is approximately the activity of 1 gram of radium. Generally speaking, radioactive samples with an activity of 1 µci or less are fairly safe to handle and can be purchased without a license from the NRC (Nuclear Regulatory Commission). Sources of 1 mci or greater can be quite dangerous. Their use is carefully regulated and they must be handled with the utmost respect. Another unit of radiation is the rad, (short for radiation absorbed dose),

2 Experiment O1 page 2 of 13 which describes the dose which an exposed person receives. A rad is the amount of radiation which deposits 0.01 J of energy into 1 kg of absorbing material. Neither the curie nor the rad can be used to adequately describe the biological damage due to radiation, because such damage depends strongly on the type of the radiation. α is the most dangerous, followed by β, then γ. A 1 rad dose of α radiation does about 20 times more damage to cell tissue than a 1 rad dose of γ radiation. The rem is a unit, which takes into account both the dose in rad and the type of radiation. dose in rem = dose in rad RBE factor (relative biological effectiveness) RBE = 1 for γ, 1.6 for β, and 20 for α. source/situation dose effect neutron bomb blast >100,000 rem immediate death Chernobyl firefighter 400 rem 50% probability of death within 30 days space shuttle astronaut 25 rem (from cosmic rays) cancer risk accidental exposure 10 rem blood changes barely detectable max. allowed exposure for radiation workers radon exposure (avg. US) 200 mrem = 0.2 rem/yr probably none other terrestrial sources 40 mrem/year probably none cosmic radiation (sea level) 30 mrem/ year probably none single chest x-ray 20 mrem probably none nuclear fallout + 3 mrem/year probably none nuclear power plant leakage total average dose (US citizens) 5 rem over 1 year no blood changes detectable, negligible increased risk of cancer mrem/year probably none 350 mrem/year probably none The numbers in the table above generally refer to whole-body exposure. During radiation treatments, cancer patients typically receive 6000 rem, but in a very localized region (the tumor, which is killed!). Geiger Counters A Geiger counter is a simple device for measuring radioactivity. It consists of a metal tube containing a low pressure gas and a wire along its central axis. The wire is held at a high positive voltage ( V). One end of the tube usually has a very thin (and fragile!) window, made of some low-atomic mass material, such as mica or beryllium, through which ionizing radiation can easily enter. A single γ or β particle entering the Geiger tube can collide with a gas atom and ionize it, stripping it of some electrons. These electrons are accelerated toward the positive central wire by the strong electric field between the grounded outer case and the high-voltage wire. They collide with other atoms, causing further ionization, resulting in avalanche of ionization events and a pulse of current which is detected by external circuitry, incrementing a counter and making an audible chirp in a speaker. In this way, a single high-

3 Experiment O1 page 3 of 13 energy particle can produce a large, brief signal which is easily distinguished from electronic noise. The mica windows on our Geiger counters, although quite thin, are too thick to allow the passage of α particles. β particles can pass through the mica window, but not the aluminum sides of the tube. γ particles can enter the tube from all directions: front, back and sides. The detection efficiency of Geiger counters for γ rays is only about 1%, that is, for every 100 γ-ray photons which pass through the detector, only one triggers an ionization avalanche. The detection efficiency for β particles is about 90%. Counting Statistics Radioactive decay is a random process. Suppose that in a particular experiment, N counts are recorded in a time T. Then the counting rate, for that trial, is R = N/T. If the average counting rate is (the bar means that the average is taken over many trials), then any particular trial will result in a measured R which will probably be close to, but not exactly equal to. A very similar situation occurs if you flip a coin many times: the number of heads will be close to, but seldom exactly equal to, the number of tails. In such cases, the counting statistics have a simple rule, called the rule: If the number of counts recorded in a time T is N, then the uncertainty in the number of counts is. That is, if you repeat the experiment many times, you will get a gaussian distribution of N s, centered on, the average value of N, with a standard deviation of. If you do the experiment just once, then the best estimate of the count is, and the best estimate of the count rate is. (There is very little uncertainty in the time measurement.) The fractional uncertainty of the count is equal to the

4 Experiment O1 page 4 of 13 fractional uncertainty of the count rate since so we have. Notice that the fractional uncertainty decreases as N increases. When you measure the count rate near a radioactive source, the Geiger counter always measures the total rate due to the source and the background. How do you remove the background from the measured rate to get the rate due to the source only, and how does this affect your uncertainty? This question is particularly important if you suspect that you are near a weak source of radioactivity, a source which increases the radioactivity at your location only slightly above background. How do you decide whether the source is actually present? If a Geiger counter counts for some period T, the total count N T will be the count due to the source N S plus the count due to the background N B. (1) or, written in terms of rates, (2). The background rate R B can be determined simply by eliminating the source and re-measuring the rate with the Geiger counter. The rate due to the source alone is; (3). To get the uncertainty in R S, δr S, we use the rule for propagation of errors in addition or subtraction: (4). Example: A Geiger counter is placed near a suspected source of radioactivity and it records 58 counts in 30 sec. The source is removed and the background count is found to be 48 counts in 30 sec. Can we be sure that the source is truly radioactive? Answer: The total count rate is. The background count rate is.

5 Experiment O1 page 5 of 13 The computed source count rate is The uncertainty in the source rate is given by. The computed source rate is R S = 20 ± 21 ct/min. So, based on the available data, it is quite possible that the increased count observed when the suspected source was present was simply a random fluctuation and not due to increased radioactivity. Longer counting times would be required to resolve the issue. Procedure Our radioactive sample is the naturally-occurring element thorium (Z=90). Because thorium oxide is able to withstand white-hot temperatures, it is sometimes used to make the high temperature mantles for gas-driven Coleman lanterns. In fact, our sample is a lantern mantle purchased at McGucken's Hardware. It has an activity of about 1 µci and it is relatively safe to handle. If you carried it in your pocket for several days, your dose would be a few times greater than that due to natural background radiation, but less than a chest x-ray. Nevertheless, you should treat all radioactive sources with a healthy respect. Never touch a radioactive source with your hands. That is why we have the source sealed in a plastic bag. Thorium decays in a chain of alpha, beta and gamma radiations, ending up after billions of years as stable lead. The alpha particles cannot penetrate the plastic sample container (but do not open it, lest the material be ingested!), but the gamma rays come out quite freely, absorbed only by lead or other heavy elements. Most of the beta rays penetrate the plastic bag. Your experiment will be to verify the quantitative law that describes how the beta rays from thorium are absorbed in sheets of absorbing material cardboard in our case. Due to the large beta emission rate of thorium and the high sensitivity of the Geiger counter to beta rays, the detected beta rate is significantly larger than the detected gamma rate. In this lab, you will compute the beta rates by measuring the total rate (beta+gamma+background) and then subtracting the (gamma+background) rate. Before turning on the Geiger counter, make sure that the Voltage Adjust knob (on the right) is turned all the way down (CCW). Turn on the counter, and press the MODE button a few times until the volts label is illuminated. The display now reads the voltage on the Geiger counter tube. Slowly, turn up the voltage until the voltage reads (the exact voltage is not critical). You will begin to hear the counter chirp occasionally as it detects natural background radiation.

6 Experiment O1 page 6 of 13 By pressing the MODE button, you can cycle the counter through several operating modes labeled 100, 1000, 4000, 15 sec, and 60 sec. In the 100 mode, when the RESET button is pushed, the counter records the next 100 counts and then computes the counts/min. During the counting, the display reads the total counts so far, but at the end of 100 counts, the display is the counts/min. Since the total count is 100, the uncertainty in the count is, and the fractional uncertainty of the count and count rate is. In the 1000 mode, the fractional uncertainty is. In the 4000 mode, it is. In the 15 sec mode, when the RESET button is pushed, the counter records counts for the next 15 sec and then computes and displays the counts/min. During the counting, the display shows the remaining time. Since the counts/min was computed based on a recorded counts in 15 sec = 0.25 min, the number N of actual counts is 1/4 of the displayed counts/min. From this, the fractional uncertainty in the count,, which is the same as the fractional uncertainty in the rate, counts/min, can be computed. In the 60 sec mode, the counter records for 60 sec = 1 min, so the final displayed counts/min is the same as the count N, and the fractional uncertainty is simply. Part 1. Measurement of gamma rate and background rate In this part, your goal is to measure the count rate due to gamma emission and natural background radioactivity, with an accuracy of better than 10%. Although we could use the Geiger counter in the 1000 mode and get an uncertainty of, this would take an inconveniently long time, because the background count rate is rather low. Making a single measurement with the Geiger counter in the 100 mode or the 60 second mode would not take long; unfortunately, that would not provide the necessary accuracy. To get the necessary accuracy, but not take too long, we are going to use Geiger counter in the 60 sec mode, but make 5 trials and combine the results. We will begin by measuring the rate due to natural background radiation only. Leave the radiation source behind the lead bricks inside the door of the 1140 folder room. With the Geiger counter in the 60 sec mode, measure the background count. Repeat for 4 more trials. Using your data for all 5 trials (total time of 5 min), compute the background rate (in counts/min)

7 Experiment O1 page 7 of 13 and its uncertainty. To do this, just imagine that instead of five 1-min counts, you performed a single 5-min count. The total count for the 5 min period is the sum of the 1-min counts, and the total time is T = 5 min. The rate is and the uncertainty is. In order to measure the gamma + background rate, we will measure the count rate from the source with an absorber that will shield the detector from the beta rays, but allow the gamma rays to pass. Obtain the radiation source from behind the lead bricks inside the 1140 notebook room. Place the source in the bottom tray under the Geiger counter tube. You should hear the rate on the counter increase dramatically. Once you start taking data with the source present, be very careful not to move the source, since the detected rate is sensitive to the detector/source geometry. Now place the thick plastic slab between the source and the detector. (Placing a sheet of cardboard in the top slot will provide a platform for the plastic slab.) This will effectively stop all the beta's but will not significantly reduce the gamma rate. Repeat the counting procedure to determine the (gamma+background) rate. Part 2. Penetration of beta s through cardboard sheets Remember: be careful not to move the source until you are done taking data. With no absorbers present, use the Geiger counter in the 1000 mode or the 60 s mode (up to you) to measure the rate due to the beta's+gamma's+ background. Then compute the rate due to the betas only and compute its uncertainty. (Remember, in the 1000 mode, the Geiger counts to N=1000, and then computes the rate R. You do not know the time T, so you can t use the formula. Instead, you must use.) There are several cardboard sheets which can be placed in the slots in the tray between the source and the Geiger tube. Stack the sheets all at the top slot, nearest the detector. That way the source is completely blocked by the sheets. Using either the 1000 mode or the 60 mode, measure the rate with varying number n of cardboard sheets. For each n, compute the rate due to the beta's only and its uncertainty. Finally, make a graph with error bars of the beta rate R vs. number of sheets n. You decide how many data points are appropriate and how long to take data in order to get reasonable statistics. Describe or justify, in your report, how you chose the number of data points and counting time to give reasonable statistics. Make an error bar plot showing a graph of the Rate vs. Number of Cardboard Sheets. To make an error bar plot in Mathematica, see the addendum at the end of the instructions for this experiment. The flux of beta s which can penetrate a cardboard wall decreases with increasing thickness of the wall. Experimentally, it is found the attenuation rate is exponential. If R o is the rate measured with no wall present, then the rate with a cardboard wall of thickness x is given by (5),

8 Experiment O1 page 8 of 13 where λ, called the penetration depth, is the thickness at which the measured rate has dropped by a factor of 1/e. At a thickness of 2λ, the rate is down to R o /e 2. At 3λ, the rate is down to R o /e 3, etc. By taking the natural log of both sides of eq n(4), we obtain (5) Thus, a graph of ln R vs. x should be a straight line with slope = -1/λ. Measure the thickness of the cardboard sheets with the micrometer. Make several measurements and average the results to get a good value. If the number of sheets is n, then the total thickness is, and eq n (5) can be written as (6) Thus a graph of ln(r) vs. n should be a straight line with slope m = x o /λ. Using your measured R s, make a graph with error bars of ln(r) vs. n. Determine the slope m and the intercept b of the best-fit line using the file ErrorLinfit.nb, which computes the best fit line to any x-y data with error bars. The file ErrorLinfit.nb is in the scratch folder located on the desktop of the lab computers. In Mathematica, open ErrorLinfit.nb, enter your x-y data (x = n, y = ln(r)) and ErrorLinfit computes m, b, δm, and δb. From your computed m and b, ErrorLinfit will plot the best fit line on your graph of ln(r) vs. n. From the fitted slope, compute the penetration depth. Radiation workers usually indicate the thickness of a barrier by giving its areal density (mass per area) rather than the thickness. Consider a sheet with thickness x, density ρ, and area A. The mass of the sheet is density volume = ρ A x, and the area density (usually denoted by µ) is µ = mass/area = ρ A x /A = ρ x. Notice that the areal density µ is proportional to thickness x. A x Use the sensitive digital scale to determine the areal density µ 0 in gram/cm 2 of a sheet of cardboard. Explain your procedure and estimate (roughly) the uncertainty in your result. Convert your penetration depth λ into the corresponding penetration areal density µ e (it s labeled µ e because that is the value of µ at which the rate drops by a factor of e ). It might help to notice x0 ρ x0 µ 0 that = =. Report the value of µ e ± δµ e λ ρ λ µ e

9 Experiment O1 page 9 of 13 In all the other labs in Physics 1140, there is a "comparison moment" when you can compare two different ways of measuring the same quantity, or you can compare your measurement with an accepted value, e.g. the known index of refraction for lucite. At these moments, you have the opportunity to see how the discrepancy compares to your estimated error. Lab O1 is different in this respect. Instead of comparing your value for the absorption length in cardboard with some known value, please comment in a quantitative way on how well the error bars on your individual points "hook" the fit curve. Recall that if the errors are purely random, and if the absorption is well-explained by a single exponential, one expects about one point in three to miss the curve by more than their error bar, and perhaps one point in 20 to miss by more than twice their error bar, but only one in 300 to miss by as many as three times the error bar.

10 Experiment O1 page 10 of 13 Guiding Questions 1. Using a Geiger counter, a radiation safety technician records 200 counts in 50 seconds. What is the count rate in counts/min? What is the uncertainty in the count rate in counts/min? 2. (Counts as two questions) A Geiger counter measures background radiation and records 950 counts in 10 minutes. Then the Geiger counter is brought near a radioactive source and it records 1430 counts in 10 minutes. Compute R S, the rate (in counts/min) due to the source only. Also compute δr S, the uncertainty in the rate due to the source only. 3. Which kind of radiation (α, β, or γ) is the most penetrating? Which kind is the most effective in doing damage to biological organisms? 4. In the 1000 mode, the Geiger counter records a rate R1 = 400 counts per minute. What is In 100 mode, the Geiger counter records a rate R2 = 400 counts per minute. What is? 5. In this lab, you are to make a graph of ln(r) vs. n. If your measured rate R has an uncertainty δr, then what is δ(lnr), the uncertainty in lnr? [Hint: if f = f(x), then.] 6. In this lab, you use a program called ErrorLinfit.nb to determine the slope m of the graph of ln(r) vs. n. The program ErrorLinfit.nb also gives the uncertainty δm. How do you compute the penetration depth λ and the uncertainty δλ from the slope m and the uncertainty δm? 7. Suppose, in this experiment, the penetration depth λ in cardboard is 3.0 mm (which is not far from the truth). How many sheets of thickness x 0 = 0.7 mm are needed to reduce the rate to (1/e) 2 of the rate R 0? (R o is the rate with no sheets.) 8. Sketch what your graph of ln(r) vs. n should look like? (No numbers! Just a qualitative sketch). What are the slope and intercept of this graph? 9. Suppose the background rate is measured 5 times with the Geiger counter in 60 sec mode. The 5 readings of the Geiger counter are 50, 57, 49, 55, and 51 (all in cts/min). From these data, compute the best value of the background rate R b, and the uncertainty.

11 Experiment O1 page 11 of 13 Pre-lab assignment for O1: Radioactivity and Counting Statistics. This prelab is designed to focus your attention on what is important in the lab before you start the experiment and give you a leg up on writing your report. Use this template when you write your report. 1. Carefully read the lab instructions for O1 2. Using Mathematica, set up a template for your lab report. This will include: I. Header information such as title, author, lab partner, and lab section: (to do this, In Mathematica, go to File, Print Settings, Header and Footer from this dialog box you can enter all of the required information.) Mathematica automatically enters the file name in the right side of the header. Leave this alone. II. Section Headings including Title, Summary of Experiment, Data and Calculations, Discussion of Uncertainty, and specific section headings for each part of the experiment. (All of the Physics 1140 lab manuals include multiple parts.) 3. Write a Summary of the experiment. What are you going to measure and what data will you collect to make the measurement? (For example, in part one of M1, you will measure the length of a pendulum along with the period of the pendulum to determine the acceleration due to gravity.) 4. For each part of the lab do the following: A.) For Part 1, why do we measure the background radiation along with the gamma radiation produced by our radiation source? What will we use this for in the following parts of the experiment? B.) For Part 2, use equation 5 for inspiration and create a theoretical graph showing the rate versus thicknesses, x. Suppose your initial rate is 10,500 counts per second and the penetration depth, λ, is 3.0mm. I. Plot your theory or expectation as a line. (In Mathematica, you should define a function and plot it using the command Plot ) Reference the Mathematica tutorial to do this. II. III. IV. Label your axes, in English (not just symbols) and with units. Include a brief caption (namely, a text statement of what the plot shows.) Set the x and y range of the plot to be close to what you expect for your data. For example: in M1 your longest length pendulum should be no more than 130 cm in length. 5. Write a Discussion of Uncertainty. What are the major sources of uncertainty in the experiment and how will you account for them?

12 Experiment O1 page 12 of Turn in a printout of your Mathematica document that includes 2-5 above. This document should be no more than 2 pages long.

13 Experiment O1 page 13 of 13 Lab O1: Making an Error Bar Plot This addendum will show you how to make an error bar plot in Mathematica. The first thing to do is to call the ErrorBarPlots package for Mathematica by typing the following and evaluating: In[136]:= Next, enter the data to plot. We will use example data from the O1 lab to plot. We enter the x and y data and then the error on the y data. In this case, the y data is radiation counts/sec and the uncertainty in that data is just the square root of the data. In[137]:= x = 80, 1, 2, 3, 4, 5, 6, 7< y = 81039, 702, 528, 414, 323, 241, 177, 131< dy = y êê N Out[137]= 80, 1, 2, 3, 4, 5, 6, 7< Out[138]= 81039, 702, 528, 414, 323, 241, 177, 131< Out[139]= , , , , , , , < Now thread the x and y data to create the ordered pairs to graph and then prepare the uncertainty data to be used in the error bar plot and thread that with the x and y data that has already been threaded together. In[140]:= xvsy = Thread@8x, y<d H*Thread x and y data to create ordered pairs*l dy2 = Table@ErrorBar@dy@@iDDD, 8i, 1, 8<D H*Prepare the uncertainty data to create the error bars on the graph. Index HiL from 1 to 8 for the eight data points we have in this case. Yours will vary on the number of data points*l xvsytotal = Thread@8xvsy, dy2<d errorplot = ErrorListPlot@xvsytotalD Out[140]= 880, 1039<, 81, 702<, 82, 528<, 83, 414<, 84, 323<, 85, 241<, 86, 177<, 87, 131<< Out[141]= 8ErrorBar@ D, ErrorBar@ D, ErrorBar@ D, ErrorBar@20.347D, ErrorBar@ D, ErrorBar@ D, ErrorBar@ D, ErrorBar@ D< Out[142]= 8880, 1039<, ErrorBar@ D<, 881, 702<, ErrorBar@ D<, 882, 528<, ErrorBar@ D<, 883, 414<, ErrorBar@20.347D<, 884, 323<, ErrorBar@ D<, 885, 241<, ErrorBar@ D<, 886, 177<, ErrorBar@ D<, 887, 131<, ErrorBar@ D<< Out[143]=

Experiment O1 page 1 of 11. Lab O1: Radioactivity and Counting Statistics

Experiment O1 page 1 of 11. Lab O1: Radioactivity and Counting Statistics Experiment O1 page 1 of 11 Lab O1: Radioactivity and Counting Statistics Radioactivity Radioactivity is a type of nuclear reaction, that is, a reaction which involve the breaking of nuclear bonds having

More information

Experiment O1 page 1 of 10. Lab O1: Radioactivity and Counting Statistics

Experiment O1 page 1 of 10. Lab O1: Radioactivity and Counting Statistics Experiment O1 page 1 of 10 Lab O1: Radioactivity and Counting Statistics Radioactivity Radioactivity is a type of nuclear reaction, that is, a reaction which involve the breaking of nuclear bonds having

More information

Radioactivity INTRODUCTION. Natural Radiation in the Background. Radioactive Decay

Radioactivity INTRODUCTION. Natural Radiation in the Background. Radioactive Decay Radioactivity INTRODUCTION The most common form of radiation is the electromagnetic wave. These waves include low energy radio waves, microwaves, visible light, x-rays, and high-energy gamma rays. Electromagnetic

More information

Radiation and Radioactivity. PHYS 0219 Radiation and Radioactivity

Radiation and Radioactivity. PHYS 0219 Radiation and Radioactivity Radiation and Radioactivity 1 Radiation and Radioactivity This experiment has four parts: 1. Counting Statistics 2. Gamma (g) Ray Absorption Half-length and shielding 3. 137 Ba Decay Half-life 4. Dosimetry

More information

Overview: In this experiment we will study the decay of a radioactive nucleus, Cesium. Figure 1: The Decay Modes of Cesium 137

Overview: In this experiment we will study the decay of a radioactive nucleus, Cesium. Figure 1: The Decay Modes of Cesium 137 Radioactivity (Part I and Part II) Objectives: To measure the absorption of beta and gamma rays To understand the concept of half life and to measure the half life of Ba 137* Apparatus: Radioactive source,

More information

Overview: In this experiment we study the decay of a radioactive nucleus, Cesium 137. Figure 1: The Decay Modes of Cesium 137

Overview: In this experiment we study the decay of a radioactive nucleus, Cesium 137. Figure 1: The Decay Modes of Cesium 137 Radioactivity (Part I and Part II) 7-MAC Objectives: To measure the absorption of beta and gamma rays To understand the concept of half life and to measure the half life of Ba 137* Apparatus: Radioactive

More information

11 Gamma Ray Energy and Absorption

11 Gamma Ray Energy and Absorption 11 Gamma Ray Energy and Absorption Before starting this laboratory, we must review the physiological effects and the proper use of the radioactive samples you will be using during the experiment. Physiological

More information

EXPERIMENT 11: NUCLEAR RADIATION

EXPERIMENT 11: NUCLEAR RADIATION Introduction: radioactive nuclei. third is electromagnetic radiation. EXPERIMENT 11: NUCLEAR RADIATION In this lab, you will be investigating three types of emissions from Two types of these emissions

More information

Nuclear Spectroscopy: Radioactivity and Half Life

Nuclear Spectroscopy: Radioactivity and Half Life Particle and Spectroscopy: and Half Life 02/08/2018 My Office Hours: Thursday 1:00-3:00 PM 212 Keen Building Outline 1 2 3 4 5 Some nuclei are unstable and decay spontaneously into two or more particles.

More information

College Physics B - PHY2054C

College Physics B - PHY2054C College - PHY2054C Physics - Radioactivity 11/24/2014 My Office Hours: Tuesday 10:00 AM - Noon 206 Keen Building Review Question 1 Isotopes of an element A have the same number of protons and electrons,

More information

Lab 12. Radioactivity

Lab 12. Radioactivity Lab 12. Radioactivity Goals To gain a better understanding of naturally-occurring and man-made radiation sources. To use a Geiger-Müller tube to detect both beta and gamma radiation. To measure the amount

More information

Activity 11 Solutions: Ionizing Radiation II

Activity 11 Solutions: Ionizing Radiation II Activity 11 Solutions: Ionizing Radiation II 11.1 Additional Sources of Ionizing Radiation 1) Cosmic Rays Your instructor will show you radiation events in a cloud chamber. Look for vapor trails that do

More information

Nicholas J. Giordano. Chapter 30. Nuclear Physics. Marilyn Akins, PhD Broome Community College

Nicholas J. Giordano.   Chapter 30. Nuclear Physics. Marilyn Akins, PhD Broome Community College Nicholas J. Giordano www.cengage.com/physics/giordano Chapter 30 Nuclear Physics Marilyn Akins, PhD Broome Community College Atomic Nuclei Rutherford s discovery of the atomic nucleus caused scientists

More information

PS-21 First Spring Institute say : Teaching Physical Science. Radioactivity

PS-21 First Spring Institute say : Teaching Physical Science. Radioactivity PS-21 First Spring Institute say 2012-2013: Teaching Physical Science Radioactivity What Is Radioactivity? Radioactivity is the release of tiny, highenergy particles or gamma rays from the nucleus of an

More information

Radioactivity APPARATUS INTRODUCTION PROCEDURE

Radioactivity APPARATUS INTRODUCTION PROCEDURE Radioactivity APPARATUS. Geiger Counter / Scaler. Cesium-7 sealed radioactive source. 0 pieces of paper. 8 aluminum plates. 0 lead plates 6. Graph paper - log-log and semi-log 7. Survey Meter ( unit for

More information

Chapter 29. Nuclear Physics

Chapter 29. Nuclear Physics Chapter 29 Nuclear Physics Ernest Rutherford 1871 1937 Discovery that atoms could be broken apart Studied radioactivity Nobel prize in 1908 Some Properties of Nuclei All nuclei are composed of protons

More information

L-35 Modern Physics-3 Nuclear Physics 29:006 FINAL EXAM. Structure of the nucleus. The atom and the nucleus. Nuclear Terminology

L-35 Modern Physics-3 Nuclear Physics 29:006 FINAL EXAM. Structure of the nucleus. The atom and the nucleus. Nuclear Terminology 9:006 FINAL EXAM L-5 Modern Physics- Nuclear Physics The final exam is on Monday MAY 7:0 AM - 9:0 AM in W90 CB The FE is not cumulative, and will cover lectures through 6. (50 questions) The last regular

More information

10.1 RADIOACTIVE DECAY

10.1 RADIOACTIVE DECAY 10.1 RADIOACTIVE DECAY When Henri Becquerel placed uranium salts on a photographic plate and then developed the plate, he found a foggy image. The image was caused by rays that had not been observed before.

More information

Lecture Presentation. Chapter 21. Nuclear Chemistry. James F. Kirby Quinnipiac University Hamden, CT Pearson Education, Inc.

Lecture Presentation. Chapter 21. Nuclear Chemistry. James F. Kirby Quinnipiac University Hamden, CT Pearson Education, Inc. Lecture Presentation Chapter 21, Inc. James F. Kirby Quinnipiac University Hamden, CT Energy: Chemical vs. Chemical energy is associated with making and breaking chemical bonds. energy is enormous in comparison.

More information

Radioactivity. General Physics II PHYS 111. King Saud University College of Applied Studies and Community Service Department of Natural Sciences

Radioactivity. General Physics II PHYS 111. King Saud University College of Applied Studies and Community Service Department of Natural Sciences King Saud University College of Applied Studies and Community Service Department of Natural Sciences Radioactivity General Physics II PHYS 111 Nouf Alkathran nalkathran@ksu.edu.sa Outline Radioactive Decay

More information

What happens during nuclear decay? During nuclear decay, atoms of one element can change into atoms of a different element altogether.

What happens during nuclear decay? During nuclear decay, atoms of one element can change into atoms of a different element altogether. When Henri Becquerel placed uranium salts on a photographic plate and then developed the plate, he found a foggy image. The image was caused by rays that had not been observed before. For his discovery

More information

WHAT IS IONIZING RADIATION

WHAT IS IONIZING RADIATION WHAT IS IONIZING RADIATION Margarita Saraví National Atomic Energy Commission - Argentina Workshop on Ionizing Radiation SIM Buenos Aires 10 November 2011 What is ionizing radiation? What is ionizing radiation?

More information

MASS ATTENUATION COEFFICIENT OF LEAD

MASS ATTENUATION COEFFICIENT OF LEAD OBJECTIVE MASS ATTENUATION COEFFICIENT OF LEAD The objective of this experiment is to measure the mass attenuation coefficient of lead by manipulating Beer-Lambert s law of attenuation. INTRODUCTION Background

More information

Chapter 30 Nuclear Physics and Radioactivity

Chapter 30 Nuclear Physics and Radioactivity Chapter 30 Nuclear Physics and Radioactivity 30.1 Structure and Properties of the Nucleus Nucleus is made of protons and neutrons Proton has positive charge: Neutron is electrically neutral: 30.1 Structure

More information

Alpha decay usually occurs in heavy nuclei such as uranium or plutonium, and therefore is a major part of the radioactive fallout from a nuclear

Alpha decay usually occurs in heavy nuclei such as uranium or plutonium, and therefore is a major part of the radioactive fallout from a nuclear Radioactive Decay Radioactivity is the spontaneous disintegration of atomic nuclei. This phenomenon was first reported in 1896 by the French physicist Henri Becquerel. Marie Curie and her husband Pierre

More information

Number of protons. 2. What is the nuclear symbol for a radioactive isotope of copper with a mass number of 60? A) Cu

Number of protons. 2. What is the nuclear symbol for a radioactive isotope of copper with a mass number of 60? A) Cu Chapter 5 Nuclear Chemistry Practice Problems 1. Fill in the missing information in the chart: Medical Use Atomic Mass symbol number Heart imaging 201 Tl 81 Number of protons Number of neutrons Abdominal

More information

Radioactive nuclei. From Last Time. Biological effects of radiation. Radioactive decay. A random process. Radioactive tracers. e r t.

Radioactive nuclei. From Last Time. Biological effects of radiation. Radioactive decay. A random process. Radioactive tracers. e r t. From Last Time Nuclear structure and isotopes Binding energy of nuclei Radioactive nuclei Final Exam is Mon Dec 21, 5:05 pm - 7:05 pm 2103 Chamberlin 3 equation sheets allowed About 30% on new material

More information

Absorption of Gamma Rays

Absorption of Gamma Rays Introduction Absorption of Gamma Rays In this experiment, the absorption coefficient of gamma rays passing through several materials is studied. The materials will be compared to one another on their efficacy

More information

RADIOACTIVITY MATERIALS: PURPOSE: LEARNING OBJECTIVES: DISCUSSION:

RADIOACTIVITY MATERIALS: PURPOSE: LEARNING OBJECTIVES: DISCUSSION: RADIOACTIVITY This laboratory experiment was largely adapted from an experiment from the United States Naval Academy Chemistry Department MATERIALS: (total amounts per lab) small bottle of KCl; isogenerator

More information

change in distance change in time

change in distance change in time M2.1 Lab M2. Ultrasound: Interference, Wavelength, and Velocity The purpose of this exercise is to become familiar with the properties of waves: frequency, wavelength, phase, and velocity. We use ultrasonic

More information

INVESTIGATING RADIOACTIVITY

INVESTIGATING RADIOACTIVITY INVESTIGATING RADIOACTIVITY OBJECTIVE: 1. To see how to measure radioactivity. 2. To see the statistical nature of radioactivity. 3. To observe how nuclear radiation decreases due to a) spreading out b)

More information

PHYSICS 176 UNIVERSITY PHYSICS LAB II. Experiment 13. Radioactivity, Radiation and Isotopes

PHYSICS 176 UNIVERSITY PHYSICS LAB II. Experiment 13. Radioactivity, Radiation and Isotopes PHYSICS 176 UNIVERSITY PHYSICS LAB II Experiment 13 Radioactivity, Radiation and Isotopes Equipment: ST-360 Counter with GM Tube and stand, shelf stand, and a source holder with isotopes. Historical overview:

More information

Experiment: Nuclear Chemistry 1

Experiment: Nuclear Chemistry 1 Experiment: Nuclear Chemistry 1 Introduction Radiation is all around us. There are two main types of radiation: ionizing and non-ionizing. We will focus on radioactivity or ionizing radiation (though non-ionizing

More information

Physics 219 Help Session. Date: Wed 12/07, Time: 6:00-8:00 pm. Location: Physics 331

Physics 219 Help Session. Date: Wed 12/07, Time: 6:00-8:00 pm. Location: Physics 331 Lecture 25-1 Physics 219 Help Session Date: Wed 12/07, 2016. Time: 6:00-8:00 pm Location: Physics 331 Lecture 25-2 Final Exam Dec. 14. 2016. 1:00-3:00pm in Phys. 112 Bring your ID card, your calculator

More information

PHYS 391 Lab 2b: Counting Statistics

PHYS 391 Lab 2b: Counting Statistics Key Concepts Ionizing Radiation Counting Statistics Poisson Distribution Inverse Square Law 2.1 Introduction PHYS 391 Lab 2b: Counting Statistics This lab will explore the statistical properties of counting

More information

R A D I A T I O N P R O T E C T I O N a n d t h e N R C

R A D I A T I O N P R O T E C T I O N a n d t h e N R C R A D I A T I O N P R O T E C T I O N and the NRC Radiation is all around us. It is naturally present in our environment and has been since before the birth of this planet. Radiation occurs in nature,

More information

Analyzing Radiation. Pre-Lab Exercise Type of Radiation Alpha Particle Beta Particle Gamma Ray. Mass (amu) 4 1/2000 0

Analyzing Radiation. Pre-Lab Exercise Type of Radiation Alpha Particle Beta Particle Gamma Ray. Mass (amu) 4 1/2000 0 Analyzing Radiation Introduction Radiation has always been a natural part of our environment. Radiation on earth comes from many natural sources; the origin of all types of naturally occurring radiation

More information

Radioactivity. General Physics II PHYS 111. King Saud University College of Applied Studies and Community Service Department of Natural Sciences

Radioactivity. General Physics II PHYS 111. King Saud University College of Applied Studies and Community Service Department of Natural Sciences King Saud University College of Applied Studies and Community Service Department of Natural Sciences Radioactivity General Physics II PHYS 111 Nouf Alkathran nalkathran@ksu.edu.sa Outline Radioactive Decay

More information

Wallace Hall Academy Physics Department. Radiation. Pupil Notes Name:

Wallace Hall Academy Physics Department. Radiation. Pupil Notes Name: Wallace Hall Academy Physics Department Radiation Pupil Notes Name: Learning intentions for this unit? Be able to draw and label a diagram of an atom Be able to state what alpha particles, beta particles

More information

Nuclear Reaction and Radiation Detectors

Nuclear Reaction and Radiation Detectors King Saud University College of Applied Studies and Community Service Department of Natural Sciences Nuclear Reaction and Radiation Detectors General Physics II PHYS 111 Nouf Alkathran nalkathran@ksu.edu.sa

More information

Interaction of the radiation with a molecule knocks an electron from the molecule. a. Molecule ¾ ¾ ¾ ion + e -

Interaction of the radiation with a molecule knocks an electron from the molecule. a. Molecule ¾ ¾ ¾ ion + e - Interaction of the radiation with a molecule knocks an electron from the molecule. radiation a. Molecule ¾ ¾ ¾ ion + e - This can destroy the delicate balance of chemical reactions in living cells. The

More information

Nuclear Radiation. Natural Radioactivity. A person working with radioisotopes wears protective clothing and gloves and stands behind a shield.

Nuclear Radiation. Natural Radioactivity. A person working with radioisotopes wears protective clothing and gloves and stands behind a shield. Nuclear Radiation Natural Radioactivity A person working with radioisotopes wears protective clothing and gloves and stands behind a shield. 1 Radioactive Isotopes A radioactive isotope has an unstable

More information

APPENDIX A RADIATION OVERVIEW

APPENDIX A RADIATION OVERVIEW Former NAVWPNSTA Concord, Inland Area APPENDIX A RADIATION OVERVIEW Draft ECSD-3211-0005-0004 08/2009 This page intentionally left blank. Draft ECSD-3211-0005-0004 08/2009 APPENDIX A RADIATION OVERVIEW

More information

Unit 3: Chemistry in Society Nuclear Chemistry Summary Notes

Unit 3: Chemistry in Society Nuclear Chemistry Summary Notes St Ninian s High School Chemistry Department National 5 Chemistry Unit 3: Chemistry in Society Nuclear Chemistry Summary Notes Name Learning Outcomes After completing this topic you should be able to :

More information

Physics 23 Fall 1989 Lab 5 - The Interaction of Gamma Rays with Matter

Physics 23 Fall 1989 Lab 5 - The Interaction of Gamma Rays with Matter Physics 23 Fall 1989 Lab 5 - The Interaction of Gamma Rays with Matter Theory The nuclei of radioactive atoms spontaneously decay in three ways known as alpha, beta, and gamma decay. Alpha decay occurs

More information

Updated 2013 (Mathematica Version) M1.1. Lab M1: The Simple Pendulum

Updated 2013 (Mathematica Version) M1.1. Lab M1: The Simple Pendulum Updated 2013 (Mathematica Version) M1.1 Introduction. Lab M1: The Simple Pendulum The simple pendulum is a favorite introductory exercise because Galileo's experiments on pendulums in the early 1600s are

More information

UNIT 10 RADIOACTIVITY AND NUCLEAR CHEMISTRY

UNIT 10 RADIOACTIVITY AND NUCLEAR CHEMISTRY UNIT 10 RADIOACTIVITY AND NUCLEAR CHEMISTRY student version www.toppr.com Contents (a) Types of Radiation (b) Properties of Radiation (c) Dangers of Radiation (d) Rates of radioactive decay (e) Nuclear

More information

L 37 Modern Physics [3] The atom and the nucleus. Structure of the nucleus. Terminology of nuclear physics SYMBOL FOR A NUCLEUS FOR A CHEMICAL X

L 37 Modern Physics [3] The atom and the nucleus. Structure of the nucleus. Terminology of nuclear physics SYMBOL FOR A NUCLEUS FOR A CHEMICAL X L 37 Modern Physics [3] [L37] Nuclear physics what s inside the nucleus and what holds it together what is radioactivity carbon dating [L38] Nuclear energy nuclear fission nuclear fusion nuclear reactors

More information

Lab E3: The Wheatstone Bridge

Lab E3: The Wheatstone Bridge E3.1 Lab E3: The Wheatstone Bridge Introduction The Wheatstone bridge is a circuit used to compare an unknown resistance with a known resistance. The bridge is commonly used in control circuits. For instance,

More information

Name Date Class. alpha particle radioactivity gamma ray radioisotope beta particles radiation X-ray radioactive decay

Name Date Class. alpha particle radioactivity gamma ray radioisotope beta particles radiation X-ray radioactive decay Name Date _ Class _ Nuclear Chemistry Section.1 Nuclear Radiation In your textbook, read about the terms used to describe nuclear changes. Use each of the terms below just once to complete the passage.

More information

L 36 Modern Physics [3] The atom and the nucleus. Structure of the nucleus. The structure of the nucleus SYMBOL FOR A NUCLEUS FOR A CHEMICAL X

L 36 Modern Physics [3] The atom and the nucleus. Structure of the nucleus. The structure of the nucleus SYMBOL FOR A NUCLEUS FOR A CHEMICAL X L 36 Modern Physics [3] [L36] Nuclear physics what s inside the nucleus and what holds it together what is radioactivity carbon dating [L37] Nuclear energy nuclear fission nuclear fusion nuclear reactors

More information

Name Date Class NUCLEAR RADIATION. alpha particle beta particle gamma ray

Name Date Class NUCLEAR RADIATION. alpha particle beta particle gamma ray 25.1 NUCLEAR RADIATION Section Review Objectives Explain how an unstable nucleus releases energy Describe the three main types of nuclear radiation Vocabulary radioisotopes radioactivity radiation alpha

More information

RADIOACTIVITY IN THE AIR

RADIOACTIVITY IN THE AIR RADIOACTIVITY IN THE AIR REFERENCES M. Sternheim and J. Kane, General Physics (See the discussion on Half Life) Evans, The Atomic Nucleus, pp. 518-522 Segre, Nuclei and Particles, p. 156 See HEALTH AND

More information

The detector and counter are used in an experiment to show that a radioactive source gives out alpha and beta radiation only.

The detector and counter are used in an experiment to show that a radioactive source gives out alpha and beta radiation only. ATOMS AND NUCLEAR RADIATION PART II Q1. The detector and counter are used in an experiment to show that a radioactive source gives out alpha and beta radiation only. Two different types of absorber are

More information

Introduction. Principle of Operation

Introduction. Principle of Operation Introduction Ionizing radiation that is associated with radioactivity cannot be directly detected by our senses. Ionization is the process whereby the radiation has sufficient energy to strip electrons

More information

Experiment Radioactive Decay of 220 Rn and 232 Th Physics 2150 Experiment No. 10 University of Colorado

Experiment Radioactive Decay of 220 Rn and 232 Th Physics 2150 Experiment No. 10 University of Colorado Experiment 10 1 Introduction Radioactive Decay of 220 Rn and 232 Th Physics 2150 Experiment No. 10 University of Colorado Some radioactive isotopes formed billions of years ago have half- lives so long

More information

Chapter 21

Chapter 21 Chapter 21 http://youtu.be/kwasz59f8ga Nuclear reactions involve the nucleus The nucleus opens, and protons and neutrons are rearranged. The opening of the nucleus releases a tremendous amount of energy

More information

UNIT 10 RADIOACTIVITY AND NUCLEAR CHEMISTRY

UNIT 10 RADIOACTIVITY AND NUCLEAR CHEMISTRY UNIT 10 RADIOACTIVITY AND NUCLEAR CHEMISTRY teacher version www.toppr.com Contents (a) Types of Radiation (b) Properties of Radiation (c) Dangers of Radiation (d) Rates of radioactive decay (e) Nuclear

More information

Unit 08 Nuclear Structure. Unit 08 Nuclear Structure Slide 1

Unit 08 Nuclear Structure. Unit 08 Nuclear Structure Slide 1 Unit 08 Nuclear Structure Unit 08 Nuclear Structure Slide 1 The Plan Nuclear Structure Nuclear Decays Measuring Radiation Nuclear Power Plants Major Nuclear Power Accidents New Possibilities for Nuclear

More information

Unit 6 Nuclear Radiation Parent Guide. What is radioactivity and why are things radioactive?

Unit 6 Nuclear Radiation Parent Guide. What is radioactivity and why are things radioactive? Unit 6 Nuclear Radiation Parent Guide What is radioactivity and why are things radioactive? The nucleus of an atom is comprised of subatomic particles called protons and neutrons. Protons have a positive

More information

Radiation Safety Talk. UC Santa Cruz Physics 133 Winter 2018

Radiation Safety Talk. UC Santa Cruz Physics 133 Winter 2018 Radiation Safety Talk UC Santa Cruz Physics 133 Winter 2018 Outline Types of radiation Sources of radiation Dose limits and risks ALARA principle Safety procedures Types of radiation Radiation is energy

More information

Chapter 16: Ionizing Radiation

Chapter 16: Ionizing Radiation Chapter 6: Ionizing Radiation Goals of Period 6 Section 6.: To discuss unstable nuclei and their detection Section 6.2: To describe the sources of ionizing radiation Section 6.3: To introduce three types

More information

Phys 243 Lab 7: Radioactive Half-life

Phys 243 Lab 7: Radioactive Half-life Phys 243 Lab 7: Radioactive Half-life Dr. Robert MacDonald The King s University College Winter 2013 Abstract In today s lab you ll be measuring the half-life of barium-137, a radioactive isotope of barium.

More information

Properties of the nucleus. 8.2 Nuclear Physics. Isotopes. Stable Nuclei. Size of the nucleus. Size of the nucleus

Properties of the nucleus. 8.2 Nuclear Physics. Isotopes. Stable Nuclei. Size of the nucleus. Size of the nucleus Properties of the nucleus 8. Nuclear Physics Properties of nuclei Binding Energy Radioactive decay Natural radioactivity Consists of protons and neutrons Z = no. of protons (Atomic number) N = no. of neutrons

More information

Differentiating Chemical Reactions from Nuclear Reactions

Differentiating Chemical Reactions from Nuclear Reactions Differentiating Chemical Reactions from Nuclear Reactions 1 CHEMICAL Occurs when bonds are broken or formed. Atoms remained unchanged, though may be rearranged. Involves valence electrons Small energy

More information

L 37 Modern Physics [3]

L 37 Modern Physics [3] L 37 Modern Physics [3] Nuclear physics what s inside the nucleus and what holds it together what is radioactivity carbon dating Nuclear energy nuclear fission nuclear fusion nuclear reactors nuclear weapons

More information

9 Nuclear decay Answers to exam practice questions

9 Nuclear decay Answers to exam practice questions Pages 173 178 Exam practice questions 1 X-rays are quanta of energy emitted when electrons fall to a lower energy level, and so do not emanate from the nucleus Answer D. 2 Alpha particles, being the most

More information

Question. 1. Which natural source of background radiation do you consider as dominant?

Question. 1. Which natural source of background radiation do you consider as dominant? Question 1. Which natural source of background radiation do you consider as dominant? 2. Is the radiation background constant or does it change with time and location? 3. What is the level of anthropogenic

More information

GLOSSARY OF BASIC RADIATION PROTECTION TERMINOLOGY

GLOSSARY OF BASIC RADIATION PROTECTION TERMINOLOGY GLOSSARY OF BASIC RADIATION PROTECTION TERMINOLOGY ABSORBED DOSE: The amount of energy absorbed, as a result of radiation passing through a material, per unit mass of material. Measured in rads (1 rad

More information

Radioactive Decay. Becquerel. Atomic Physics. In 1896 Henri Becquerel. - uranium compounds would fog photographic plates as if exposed to light.

Radioactive Decay. Becquerel. Atomic Physics. In 1896 Henri Becquerel. - uranium compounds would fog photographic plates as if exposed to light. Radioactive Decay Atomic Physics Becquerel In 1896 Henri Becquerel - uranium compounds would fog photographic plates as if exposed to light. - a magnetic field could deflect the radiation that caused the

More information

Ch Radioactivity. Henry Becquerel, using U-238, discovered the radioactive nature of elements in 1896.

Ch Radioactivity. Henry Becquerel, using U-238, discovered the radioactive nature of elements in 1896. Ch. 10 - Radioactivity Henry Becquerel, using U-238, discovered the radioactive nature of elements in 1896. Radioactivity the process in which an unstable atomic nucleus emits charged particles and energy

More information

Final Exam. Physics 208 Exit survey. Radioactive nuclei. Radioactive decay. Biological effects of radiation. Radioactive tracers

Final Exam. Physics 208 Exit survey. Radioactive nuclei. Radioactive decay. Biological effects of radiation. Radioactive tracers Final Exam Mon, Dec 15, at 10:05am-12:05 pm, 2103 Chamberlin 3 equation sheets allowed About 30% on new material Rest on topics of exam1, exam2, exam3. Study Tips: Download blank exams and take them. Download

More information

Shielding Alpha, Beta, and Gamma Radiation 11/08 Integrated Science 3

Shielding Alpha, Beta, and Gamma Radiation 11/08 Integrated Science 3 Shielding Alpha, Beta, and Gamma Radiation 11/08 Integrated Science 3 Name Per. Introduction The term radioactivity refers to the activity of unstable atoms. Radioactive substances send out very energetic

More information

The Atomic Nucleus & Radioactive Decay. Major Constituents of an Atom 4/28/2016. Student Learning Outcomes. Analyze radioactive decay and its results

The Atomic Nucleus & Radioactive Decay. Major Constituents of an Atom 4/28/2016. Student Learning Outcomes. Analyze radioactive decay and its results The Atomic Nucleus & Radioactive Decay ( Chapter 10) Student Learning Outcomes Analyze radioactive decay and its results Differentiate between nuclear fission and fusion Major Constituents of an Atom U=unified

More information

What is Radiation? Historical Background

What is Radiation? Historical Background What is Radiation? This section will give you some of the basic information from a quick guide of the history of radiation to some basic information to ease your mind about working with radioactive sources.

More information

Nuclear Physics Lab I: Geiger-Müller Counter and Nuclear Counting Statistics

Nuclear Physics Lab I: Geiger-Müller Counter and Nuclear Counting Statistics Nuclear Physics Lab I: Geiger-Müller Counter and Nuclear Counting Statistics PART I Geiger Tube: Optimal Operating Voltage and Resolving Time Objective: To become acquainted with the operation and characteristics

More information

General Physics (PHY 2140)

General Physics (PHY 2140) General Physics (PHY 2140) Lecture 19 Modern Physics Nuclear Physics Nuclear Reactions Medical Applications Radiation Detectors Chapter 29 http://www.physics.wayne.edu/~alan/2140website/main.htm 1 Lightning

More information

General Physics (PHY 2140)

General Physics (PHY 2140) General Physics (PHY 2140) Lightning Review Lecture 19 Modern Physics Nuclear Physics Nuclear Reactions Medical Applications Radiation Detectors Chapter 29 http://www.physics.wayne.edu/~alan/2140website/main.htm

More information

Radiation Protection Fundamentals and Biological Effects: Session 1

Radiation Protection Fundamentals and Biological Effects: Session 1 Radiation Protection Fundamentals and Biological Effects: Session 1 Reading assignment: LLE Radiological Controls Manual (LLEINST 6610): Part 1 UR Radiation Safety Training Manual and Resource Book: Parts

More information

Radioactivity. Ernest Rutherford, A New Zealand physicist proved in the early 1900s a new model of the atom.

Radioactivity. Ernest Rutherford, A New Zealand physicist proved in the early 1900s a new model of the atom. Radioactivity In 1896 Henri Becquerel on developing some photographic plates he found that the uranium emitted radiation. Becquerel had discovered radioactivity. Models of the Atom Ernest Rutherford, A

More information

Chapter 10. Section 10.1 What is Radioactivity?

Chapter 10. Section 10.1 What is Radioactivity? Chapter 10 Section 10.1 What is Radioactivity? What happens when an element undergoes radioactive decay? How does radiation affect the nucleus of an unstable isotope? How do scientists predict when an

More information

How many protons are there in the nucleus of the atom?... What is the mass number of the atom?... (Total 2 marks)

How many protons are there in the nucleus of the atom?... What is the mass number of the atom?... (Total 2 marks) Q1. The diagram shows an atom. How many protons are there in the nucleus of the atom?... What is the mass number of the atom?... (Total 2 marks) Page 1 of 53 Q2. The picture shows a man at work in a factory

More information

Chapter 28 Lecture. Nuclear Physics Pearson Education, Inc.

Chapter 28 Lecture. Nuclear Physics Pearson Education, Inc. Chapter 28 Lecture Nuclear Physics Nuclear Physics How are new elements created? What are the natural sources of ionizing radiation? How does carbon dating work? Be sure you know how to: Use the right-hand

More information

Radiation Safety Training Session 1: Radiation Protection Fundamentals and Biological Effects

Radiation Safety Training Session 1: Radiation Protection Fundamentals and Biological Effects Radiation Safety Training Session 1: Radiation Protection Fundamentals and Biological Effects Reading Assignment: LLE Radiological Controls Manual (LLEINST 6610) Part 1 UR Radiation Safety Training Manual

More information

Ch. 18 Problems, Selected solutions. Sections 18.1

Ch. 18 Problems, Selected solutions. Sections 18.1 Sections 8. 8. (I) How many ion pairs are created in a Geiger counter by a 5.4-MeV alpha particle if 80% of its energy goes to create ion pairs and 30 ev (average in gases) is required per ion pair? Notice

More information

NUCLEAR SPECTROMETRY

NUCLEAR SPECTROMETRY INTRODUCTION RADIOACTIVITY (Revised:1-24-93) The nuclei of certain atoms are stable and under ordinary circumstances, stable nuclei do not undergo change. The nuclei of other atoms are unstable. These

More information

Lecture 1 Bioradiation

Lecture 1 Bioradiation 1 1 Radiation definition: Radiation, when broadly defined, includes the entire spectrum of electromagnetic waves : radiowaves, microwaves, infrared, visible light, ultraviolet, and x-rays and particles.

More information

Dosimetry. Sanja Dolanski Babić May, 2018.

Dosimetry. Sanja Dolanski Babić May, 2018. Dosimetry Sanja Dolanski Babić May, 2018. What s the difference between radiation and radioactivity? Radiation - the process of emitting energy as waves or particles, and the radiated energy Radioactivity

More information

Chapter 18 Nuclear Chemistry

Chapter 18 Nuclear Chemistry Chapter 8 Nuclear Chemistry 8. Discovery of radioactivity 895 Roentgen discovery of radioactivity X-ray X-ray could penetrate other bodies and affect photographic plates led to the development of X-ray

More information

EXPERIMENT FOUR - RADIOACTIVITY This experiment has been largely adapted from an experiment from the United States Naval Academy, Annapolis MD

EXPERIMENT FOUR - RADIOACTIVITY This experiment has been largely adapted from an experiment from the United States Naval Academy, Annapolis MD EXPERIMENT FOUR - RADIOACTIVITY This experiment has been largely adapted from an experiment from the United States Naval Academy, Annapolis MD MATERIALS: (total amounts per lab) small bottle of KCl; isogenerator

More information

Industrial Hygiene: Assessment and Control of the Occupational Environment

Industrial Hygiene: Assessment and Control of the Occupational Environment Industrial Hygiene: Assessment and Control of the Occupational Environment Main Topics Air Pollution Control Analytical Methods Ergonomics Gas and Vapour Sampling General Practice Heat and Cold Stress

More information

Chem 1A Chapter 5 and 21 Practice Test Grosser ( )

Chem 1A Chapter 5 and 21 Practice Test Grosser ( ) Class: Date: Chem A Chapter 5 and 2 Practice Test Grosser (203-204) Multiple Choice Identify the choice that best completes the statement or answers the question.. The periodic law states that the properties

More information

Lab 14. RADIOACTIVITY

Lab 14. RADIOACTIVITY Lab 14. RADIOACTIVITY 14.1. Guiding Question What are the properties of different types of nuclear radiation? How does nucelar decay proceed over time? 14.2. Equipment 1. ST360 Radiation Counter, G-M probe

More information

Chapter 30 X Rays GOALS. When you have mastered the material in this chapter, you will be able to:

Chapter 30 X Rays GOALS. When you have mastered the material in this chapter, you will be able to: Chapter 30 X Rays GOALS When you have mastered the material in this chapter, you will be able to: Definitions Define each of the following terms, and use it in an operational definition: hard and soft

More information

Lecture Outlines Chapter 32. Physics, 3 rd Edition James S. Walker

Lecture Outlines Chapter 32. Physics, 3 rd Edition James S. Walker Lecture Outlines Chapter 32 Physics, 3 rd Edition James S. Walker 2007 Pearson Prentice Hall This work is protected by United States copyright laws and is provided solely for the use of instructors in

More information

Radioactive Decay of 220 Rn and 232 Th Physics 2150 Experiment No. 10 University of Colorado

Radioactive Decay of 220 Rn and 232 Th Physics 2150 Experiment No. 10 University of Colorado Experiment 10 1 Introduction Radioactive Decay of 220 Rn and 232 Th Physics 2150 Experiment No. 10 University of Colorado Some radioactive isotopes formed billions of years ago have half-lives so long

More information

RADIATION-METER TM-91/TM-92

RADIATION-METER TM-91/TM-92 RADIATION-METER TM-91/TM-92 User s Manual EN 1 / 16 CONTENTS 1. introduction... 3 2. Safety Precaution... 4 3. Specification... 6 4. Identifying parts... 7 5. Operation Procedure... 8 6. Battery Replacement...

More information

Read Hewitt Chapter 33

Read Hewitt Chapter 33 Cabrillo College Physics 10L LAB 6 Radioactivity Read Hewitt Chapter 33 Name What to BRING TO LAB: Any suspicious object that MIGHT be radioactive. What to explore and learn An amazing discovery was made

More information

U (superscript is mass number, subscript atomic number) - radionuclides nuclei that are radioactive - radioisotopes atoms containing radionuclides

U (superscript is mass number, subscript atomic number) - radionuclides nuclei that are radioactive - radioisotopes atoms containing radionuclides Chapter : Nuclear Chemistry. Radioactivity nucleons neutron and proton all atoms of a given element have the same number of protons, atomic number isotopes atoms with the same atomic number but different

More information

Radioactivity & Nuclear. Chemistry. Mr. Matthew Totaro Legacy High School. Chemistry

Radioactivity & Nuclear. Chemistry. Mr. Matthew Totaro Legacy High School. Chemistry Radioactivity & Nuclear Chemistry Mr. Matthew Totaro Legacy High School Chemistry The Discovery of Radioactivity Antoine-Henri Becquerel designed an experiment to determine if phosphorescent minerals also

More information