Overview: In this experiment we study the decay of a radioactive nucleus, Cesium 137. Figure 1: The Decay Modes of Cesium 137
|
|
- Byron Anderson
- 6 years ago
- Views:
Transcription
1 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 source, aluminum absorbers, lead absorbers, Geiger counter, computer interface, computer, Logger Pro software, weak HCl solution ( for Part II ) Overview: In this experiment we study the decay of a radioactive nucleus, Cesium 137 with symbol Cs 137. Cesium 137 is an artificial nucleus made in a fission reactor. It has 55 protons and 82 neutrons. It has a relatively long half life of 30 years, i.e. if you have N of these nuclei, N/2 of them will decay over the course of 30 years. Cs 137 decays by emitting a beta ray (or particle), which carries away one negative charge, converting the Cs 137 into Barium, symbol Ba 137. [When radioactivity was first discovered the nature of the various types of emitted particles was not known, so they were labeled alpha, beta, and gamma. Today we know that the alpha-ray is a He 4 nucleus, the beta-ray is an electron and the gamma-ray is a high energy photon. In beta decay the electron is emitted together with an anti-neutrino, which carries away part of the available energy.] The beta decay of Cs 137 can occur in two different ways, as shown in Fig. 1. The direct decay to the ground state of Ba 137, releasing MeV, is rather infrequent (6.5%) and we will ignore this possible mode. The other, dominant (93.5%) decay mode of Cs 137 is to an excited state Ba 137* which is metastable (i.e. it decays still further to the ground state). The released energy in this first step is MeV, which is carried away by an electron and an anti-neutrino. The half life of Ba 137* is only about 2.5 min. and it decays by gamma decay to Ba 137. This second step occurs by emission of a MeV gamma ray. Figure 1: The Decay Modes of Cesium 137 Radioactivity 1
2 We will study two aspects of the radioactivity: 1. (Part I) How does matter absorb the beta and gamma rays emitted during the decay of Cesium 137? 2. (Part II) What is the half life of the Ba 137* state? The absorption of charged particles like the beta ray by matter is fundamentally different from that of neutral gamma rays. Let us consider the beta ray first. Absorption of beta rays: When a beta ray (electron) passes through a material, there is an electric force between it and the electrons of the atoms it passes. With each "collision the beta particle gives up a little of its energy, sometimes stripping an electron from an atom, ionizing it. (This ionization is the chief cause of the biological damage done by radiation.) After many such collisions the beta's kinetic energy is converted into thermal energy of the material. The distance the beta ray travels in the material before stopping is called its range. Beta particles having the same initial energy will have virtually identical ranges. But for the decay shown in Fig. 1, the beta rays are not emitted with a single energy. This is because during the decay another particle, the anti-neutrino, which has no charge and we cannot detect, is also emitted and carries away some of the MeV released energy. The exact amount -- from zero to MeV -- that the beta ray carries depends on the angle it makes with the neutrino. Thus, the beta rays emitted during the decay will have a spread of ranges in matter from almost zero to a maximum which depends on the energy released by the parent nucleus. Increasing thicknesses of absorber will stop beta particles with larger and larger energies, up to the maximum range or stopping distance. For the radioactive source used in this experiment, a semi-log plot of the beta ray count rate vs. absorber thickness D is approximately a straight line with a sharp kink when the absorber thickness equals the stopping distance of the beta rays. For thicknesses larger than this critical thickness all beta rays are completely absorbed and the remaining radiation consists of pure gamma rays. Thus by measuring D at which the beta radiation ceases and using Fig. 2, we can determine the energy released during the beta decay. Radioactivity 2
3 E (Mev) D (mm) Figure 2. Energy Dependence of the Stopping Distance of Beta Rays in Aluminum Absorption of gamma rays: For photons the process of energy loss (i.e. gamma ray absorption) is entirely different. A gamma ray with energy less than 1 MeV as in this experiment transfers its energy to one or more electrons by one of two processes: (1) the photoelectric effect: the photon's energy is used in part to remove an electron from an atom. All of the remaining energy is given to the electron as kinetic energy; the initial photon disappears. (2) the Compton effect: only part of the photon's energy is given to an electron. The remaining energy goes into a new photon of (lower) energy (scattered in a different direction). Thus we see that beta particles dribble their energy away, a little bit at a time, until it is all gone, while photons give theirs away all at once resulting in excitation and ionization of atoms. The mechanisms by which beta rays lose energy in matter are much more efficient than for gamma rays resulting in a much shorter range for beta rays than gammas. Radioactivity 3
4 Half Life: Radioactive decay is a random process and it is impossible to predict when a particular nucleus will decay. Instead we use the probability that a nucleus will decay in one second. is a constant that is independent of time. It does not matter how long a nucleus has survived without decaying; the probability that it will decay during a time interval t is exactly the same. Then if we have N nuclei, N will reduce with time. The fraction that will decay in the short time interval t is: N N (1) t where N is the number of nuclei that decay. Eq. (1) can be rewritten as dn N. (2) dt The solution to this differential equation is the exponential function N N o e t, where No is the number of nuclei you start with at time t = 0. We are interested in the half life -- the length of time it takes for half of the nuclei to decay. Setting N = No/2 and t =, we find N o 2 N o e or Taking the natural logarithm we find e 2 ln2 (3) Apparatus: The apparatus you will use is extremely simple. You only need to launch the appropriate Logger Pro file (on your Desktop-->Course Folders161Radioactivity.N.CMBL) to measure the radiation (counts) over a certain time interval. Every time a beta or gamma ray passes into the Geiger tube, the tube emits a pulse which is counted by Logger Pro for a length of time, which is determined by which Logger Pro template file you use (Radioactivity1.CMBL, Radioactivity 2.CMBL or Radioactivity3.CMBL. After the software finishes collecting the data, the number of counts is plotted on a graph of number of counts versus elapsed time. Logger Pro offers you the option of plotting instead a histogram of the number of times a given count N is obtained in a count interval versus N. It also has an AnalyzeStatistice menu option that allows you to determine the statistics for your histogram such as the average count <N> and the standard deviation. Radioactivity 4
5 Radioactivity (prelab questions, show work) Names Section 1: "Activity" of a radioactive source is the number of radioactive decays that occur per second. The unit of activity is the Curie (Ci). [ 1 Ci = 3.7 x Bq (becquerel or disintegrations/second).] The Curie is a large unit of activity. The Cs 137 source used in this lab has an activity of 5 Ci or 5x10-6 Ci (very slowly decreasing with time). Question A. If the Geiger counter has a circular opening 0.5 cm in radius and is 2 cm away from the source, what is the count rate of a 100% efficient Geiger counter? [ Note when the Cs 137 decays, beta and gamma rays are emitted randomly in every direction. So in this example imagine a spherical surface area 4R 2 around the source, where R = 2 cm. The circular opening of the Geiger counter will only collect the radiation from a small part of that entire surface area. That small part equals an area = r 2, where r = 0.5 cm, the opening of the counter. Therefore the count rate detected by this Geiger counter is ( r 2 / 4R 2 ) times the total activity.] Question B. What is the count rate of a counter set at 4 cm from the source? Question C. How far does it have to be moved away from the source to record a count rate equal to the natural background rate (e.g. 30 counts/minute)? Radioactivity 5
6 2: Absorbed Dose and biological effect. The activity of a source does not yet tell you anything about its biological effect. The absorbed dose tells you how much energy is actually deposited in your body by the radiation. The unit of Radiation Absorbed Dose is the rad. One rad is said to have been delivered to a specific part of the body when an energy of 0.01 J/kg has been absorbed. Background radiation on earth of natural origin delivers a dose of about 0.2 rad/year. Safety Concern: A whole-body short-term gamma ray dose of 300 rad will cause death in 50% of the population. If the dose is delivered more slowly, the effect is less severe since the body has time to repair some of the damage induced by the radiation. Question A. Suppose you ingested 5 Ci of Cs 137. Estimate the maximum absorbed dose (in rad) you receive in one day if all gamma rays released in the decay were absorbed by your body. [This assumption is far from correct since the body is mostly transparent to gamma rays.] Each disintegration results in an energy release E(beta) + E(gamma) = = MeV. Question B. Estimate the change in temperature of 1 kg of water if it absorbed a dose of 300 rad. What does this imply about heating as the source of the biological damage produced by radiation? Radioactivity 6
7 Report -- Radioactivity (PART I) Name Partner Partner Section Activity 1: Absorption of Beta Rays A. Double-click on Radioactivity1a.CMBL ( to record the natural background activity. The background is partly from cosmic rays and partly from radioactive materials which are normally present in the ground, in building materials and even our bodies. It should be about 10 to 40 counts per minute. Make sure the Cs source is not located near the Geiger tube. Logger Pro will use a count interval of 1 s and a run time of 3 minutes. After the data is collected, display it as a graph and use the Analyze menu to obtain the average activity (counts/s). Include the graph in your report. Mean Background Activity c/s The background is so low that you can ignore it in this part of the experiment. You will need this background measurement for a later investigation. B. The radioactive source consists of a small, safe amount of Cs 137 covered and sealed in plastic, which emits observable beta particles and gamma rays. Place the Cs source with the aluminum side down in the holder about 2 cm below the Geiger tube. Use Logger Pro again to measure the activity. Repeat with the source located 4 cm from the tube. Include in one graph the activities for both distances. Include the graph in your report. Compare with your predictions in preliminary activity 1. 2 cm: Observed Activity c/s 4 cm: Observed Activity c/s Ratio of (2 cm/4 cm) Activity: Predicted Observed C. Put the source, aluminum side down, on the bottom slot of the stand. What is the distance between source and counter? Quit Logger Pro, then launch Radioactivity1c.CMBL; Logger Pro will count for one minute. Be sure not to move the source after taking this measurement. Put one of the thin aluminum absorbers (made of four-ply aluminum foil, total thickness mm; newer absorbers are two-ply but same total thickness) on Radioactivity 7
8 the tray between the counter and the source. Count for 30 seconds. Record the activity. Add more of the thin aluminum absorbers one at a time, and determine the counting rate each time, until it becomes approximately constant (once the rate is constant, only gamma radiation remains). In one graph show activity (and mean) for 0, 1, 2, 3, 4, 6 absorbers. Continue with more absorbers to establish this constant counting rate accurately. In a second graph show activity (and mean) for 8, 10, 12, 14, 16, 20 absorbers. Record your data in the table below. Aluminum Absorbers counting rate (c/s) Aluminum absorbers counting rate (c/s) Aluminum absorbers counting rate (c/s) Now use the data from the above table to make a semi-log plot (on the graph paper attached at the end of this report) of Activity (Counting Rate) vs. # Absorbers. The first set of data points should follow a steep straight line, the last data points follow also a straight line but much more gradual. The second line represents gamma radiation while all beta rays have been stopped. Find the beta ray's maximum Range (the distance D that the most energetic beta rays can travel before being stopped) in aluminum. From the graph in Fig. 2 (given in this manual) determine the maximum energy of the beta particles. Number of Absorbers before counting rate becomes nearly constant: Radioactivity 8
9 Total thickness of Al = Range of beta rays from this source = D: Maximum Beta Ray Energy (using Fig. 2 of this manual) Expected Maximum Beta Ray Energy (Fig. 1 of this manual) The initial counting rate (0 absorbers) includes both types of rays (beta + gamma) while the constant counting rate is due only to the gamma rays. Therefore you can answer the Question: What part of the 0-absorber count is due to beta rays and what part is due to gamma rays? Activity 2. Absorption of Gamma Rays. The purpose of this investigation is to qualitatively observe the difference in absorption between beta and gamma rays. Careful quantitative measurements are not required. A. Turn the source over so that the aluminum holder is between the counter and the source. Insert the source in the second slot. What is the distance between source and counter? The aluminum holder will absorb most of the beta rays and pass most of the gamma rays. Quit Logger Pro and launch Radioactivity2.CMBL. Logger pro will count the activity for three minutes. Again include the activities for 0, 1, 2, 3, 4 lead absorbers for this part A in one single graph. Add lead absorbers, one at a time, (plate thickness 2.78 mm), until the activity is reduced by about one half (you may need up to 4 lead absorbers). B. Total thickness of lead required to reduce gamma count rate by 1/2 = mm Which part of this count rate is due to the natural back ground? Radioactivity 9
10 Report -- Radioactivity (PART II) Name Partner Partner Section Activity 3. Half Life of Ba 137* In this investigation you will measure the approximately 2.5 minute half life of the metastable Ba 137* state. It is necessary to chemically separate the Ba 137* from the Cs 137 source so as to eliminate the beta rays that the Cs is emitting. These rays would confuse the half life measurement because your Geiger counter cannot distinguish between beta and gamma rays. Your instructor will separate the barium from the cesium by using a weak HCl solution which dissolves barium chloride. This must be done immediately before you take your Ba 137* data, as the Ba 137* half life is short and the Ba 137* activity is weak. Once your instructor gives you your sample, start taking the Ba 137* data immediately. Do not move the source or counter once you have started. Launch Radioactivity3.CMBL. Logger Pro will count with a count interval of 10 s and a run time of 10 minutes. To analyze the data for the half life, you will use the fact that the activity drops by 1/2 when you wait one half life. Because the activity is low, especially after several half lives have elapsed, you will need to subtract the background activity as follows: You measured the background activity per second before in section A of activity 1. Total activity at t = 0 s = c/ 10 s Background activity from before x 10 s = c/ 10 s Activity = Total - Background = c/ 10 s Use your result for the half life to calculate the probability that a given Ba 137* nucleus will decay in the next 5 s. Radioactivity 10
11 Optional analysis: Do the following operations in Logger Pro: Create a new column (the two existing ones are Time and Radiation) to subtract the background activity (for a 10 s interval), by going to DataNew Calculated Column and entering the proper equation. You can either type in the variable directly (as long as you surround it in quotation marks, as in Radiation ), or you can select it from the Variables (Columns) drop-down menu. Then use the natural log function (type into the equation directly or select from the Functions drop-down menu) to take the natural logarithm of the corrected activity (A-B). See below: Plot ln (A-B) versus elapsed time t. This should give you a straight line. Make a simple fit to the data (AnalyzeCurve Fit. The slopeof the fitwill be from which you can calculate using Eq. (3): = ln 2 / / Radioactivity 11
12 Radioactivity 12
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 information11 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 informationRadiation 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 informationLab NUC. Determination of Half-Life with a Geiger-Müller Counter
Lab NUC Determination of Half-Life with a Geiger-Müller Counter Object: Apparatus: To understand the concept of half-life; to become familiar with the use of a Geiger-Müller counter; to determine the half-lives
More informationRadioactivity 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 informationRadioactivity 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 informationEXPERIMENT 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 informationPhysics 1000 Half Life Lab
Physics 1000 Half Life Lab Determination of Half-Life with a Geiger-Müller Counter Object: Apparatus: To understand the concept of half-life; to become familiar with the use of a Geiger-Müller counter;
More informationA Study of Radioactivity and Determination of Half-Life
A Study of Radioactivity and Determination of Half-Life Purpose: To examine different types of radioactivity and their properties, and measure the half-life of a radioisotope Introduction A radioactive
More informationPhys 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 informationABSORPTION OF BETA AND GAMMA RADIATION
ABSORPTION OF BETA AND GAMMA RADIATION The purpose of this experiment is to understand the interaction of radiation and matter, and the application to radiation detection and shielding Apparatus: 137 Cs
More informationMASS 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 informationLECTURE 26 RADIATION AND RADIOACTIVITY. Instructor: Kazumi Tolich
LECTURE 26 RADIATION AND RADIOACTIVITY Instructor: Kazumi Tolich Lecture 26 2 30.4 Radiation and radioactivity Alpha decay Beta decay Gamma decay Decay series Nuclear radiation is a form of ionizing radiation
More informationUnit 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 informationPhysics 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 informationEXPERIMENT 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 informationAnalyzing 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 informationJazan University College of Science Physics Department. Lab Manual. Nuclear Physics (2) 462 Phys. 8 th Level. Academic Year: 1439/1440
Jazan University College of Science Physics Department جاهعة جازان كلية العل وم قسن الفيزياء Lab Manual Nuclear Physics (2) 462 Phys 8 th Level Academic Year: 1439/1440 1 Contents No. Name of the Experiment
More informationComputer 3. Lifetime Measurement
Lifetime Measurement Computer 3 The activity (in decays per second) of some radioactive samples varies in time in a particularly simple way. If the activity (R) in decays per second of a sample is proportional
More informationI. Pre-Lab Introduction
I. Pre-Lab Introduction Please complete the following pages before the lab by filling in the requested items. A. Atomic notation: Atoms are composed of a nucleus containing neutrons and protons surrounded
More information6. Atomic and Nuclear Physics
6. Atomic and Nuclear Physics Chapter 6.2 Radioactivity From IB OCC, prepared by J. Domingues based on Tsokos Physics book Warm Up Define: nucleon atomic number mass number isotope. Radioactivity In 1896,
More informationRADIOACTIVITY 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 informationDetermining the Efficiency of a Geiger Müller Tube
Determining the Efficiency of a Geiger Müller Tube Introduction Richard Born Northern Illinois University Operations Management and Information Systems The percent efficiency (ɛ of a Geiger Müller (G M)
More informationPhysics 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 informationSome nuclei are unstable Become stable by ejecting excess energy and often a particle in the process Types of radiation particle - particle
Radioactivity George Starkschall, Ph.D. Lecture Objectives Identify methods for making radioactive isotopes Recognize the various types of radioactive decay Interpret an energy level diagram for radioactive
More informationRadioactivity III: Measurement of Half Life.
PHY 192 Half Life Spring 2010 1 Radioactivity III: Measurement of Half Life. Introduction This experiment will once again use the apparatus of the first experiment, this time to measure radiation intensity
More informationChapter 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 informationBETA-RAY SPECTROMETER
14 Sep 07 β-ray.1 BETA-RAY SPECTROMETER In this experiment, a 180, constant-radius magnetic spectrometer consisting of an electromagnet with a Geiger-Muller detector, will be used to detect and analyze
More informationModern Physics Laboratory Beta Spectroscopy Experiment
Modern Physics Laboratory Beta Spectroscopy Experiment Josh Diamond and John Cummings Fall 2009 Abstract In this experiment, electrons emitted as a result of the radioactive beta decay of 137 55 Cs are
More informationNuclear 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 informationEQUIPMENT Beta spectrometer, vacuum pump, Cs-137 source, Geiger-Muller (G-M) tube, scalar
Modern Physics Laboratory Beta Spectroscopy Experiment In this experiment, electrons emitted as a result of the radioactive beta decay of Cs-137 are measured as a function of their momentum by deflecting
More informationRecap I Lecture 41 Matthias Liepe, 2012
Recap I Lecture 41 Matthias Liepe, 01 Recap II Nuclear Physics The nucleus Radioactive decay Fission Fusion Particle Physics: What is the Higgs? Today: Nuclear Physics: The Nucleus Positive charge and
More informationWhat 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 informationCh. 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 informationChapter 3 Radioactivity
Chapter 3 Radioactivity Marie Curie 1867 1934 Discovered new radioactive elements Shared Nobel Prize in physics in 1903 Nobel Prize in Chemistry in 1911 Radioactivity Radioactivity is the spontaneous emission
More informationPhysics 248, Spring 2009 Lab 6: Radiation and its Interaction with Matter
Name Section Physics 48, Spring 009 Lab 6: Radiation and its Interaction with Matter Your TA will use this sheet to score your lab. It is to be turned in at the end of lab. To receive full credit you must
More informationNicholas 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 informationDavid A. Katz Department of Chemistry Pima Community College, 2202 W. Anklam Rd. Tucson, AZ 85709, USA
EXPERIMENTS FOR NUCLEAR CHEMISTRY 2013, 2010, 2008, 2004, 1972 by David A. Katz. All rights reserved. Permission for classroom use provided original copyright is included. David A. Katz Department of Chemistry
More information3 Radioactivity - Spontaneous Nuclear Processes
3 Radioactivity - Spontaneous Nuclear Processes Becquerel was the first to detect radioactivity. In 1896 he was carrying out experiments with fluorescent salts (which contained uranium) and found that
More informationRADIOACTIVITY, BETA, AND GAMMA RAYS
July 14, 2008 Radioactivity 1 Name Date Partners RADIOACTIVITY, BETA, AND GAMMA RAYS Classic atomic and radioactive symbol OBJECTIVES OVERVIEW Learn about radioactivity. Understand the random nature of
More informationPh 3504 Radioactive Decay
Ph 3504 Radioactive Decay Required background reading Attached are several pages from an appendix on the web for Tipler. You do not have to read them all (unless you want to), but make sure you read the
More informationRadioactivity. 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 informationLifetime Measurement
Lifetime Measurement LabQuest 3 The activity (in decays per second) of some radioactive samples varies in time in a particularly simple way. If the activity (R) in decays per second of a sample is proportional
More information5 Atomic Physics. 1 of the isotope remains. 1 minute, 4. Atomic Physics. 1. Radioactivity 2. The nuclear atom
5 Atomic Physics 1. Radioactivity 2. The nuclear atom 1. In a fission reactor, which particle causes a Uranium-235 nucleus to split? A. alpha-particle B. gamma ray C. neutron D. proton 2. A radioactive
More informationGLOSSARY 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 informationAt the conclusion of this lesson the trainee will be able to: a) Write a typical equation for the production of each type of radiation.
RADIOACTIVITY - SPONTANEOUS NUCLEAR PROCESSES OBJECTIVES At the conclusion of this lesson the trainee will be able to: 1. For~, p and 7 decays a) Write a typical equation for the production of each type
More informationNuclear Chemistry. In this chapter we will look at two types of nuclear reactions.
1 1 Nuclear Chemistry In this chapter we will look at two types of nuclear reactions. Radioactive decay is the process in which a nucleus spontaneously disintegrates, giving off radiation. Nuclear bombardment
More informationPS-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 informationNuclear Chemistry. Radioactivity. In this chapter we will look at two types of nuclear reactions.
1 Nuclear Chemistry In this chapter we will look at two types of nuclear reactions. Radioactive decay is the process in which a nucleus spontaneously disintegrates, giving off radiation. Nuclear bombardment
More informationAlpha 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 informationIntroduction to Nuclear Engineering. Ahmad Al Khatibeh
Introduction to Nuclear Engineering Ahmad Al Khatibeh CONTENTS INTRODUCTION (Revision) RADIOACTIVITY Radioactive Decay Rates Units of Measurement for Radioactivity Variation of Radioactivity Over Time.
More informationRadioactivity. 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 informationLAB 13 - RADIOACTIVITY, BETA, AND GAMMA RAYS
237 Name Date Partners LAB 13 - RADIOACTIVITY, BETA, AND GAMMA RAYS OBJECTIVES Learn about radioactivity. Understand the random nature of radioactivity. Investigate the 1/r 2 dependence of particle decay.
More informationGeneral Physics (PHY 2140)
General Physics (PHY 2140) Lecture 37 Modern Physics Nuclear Physics Radioactivity Nuclear reactions http://www.physics.wayne.edu/~apetrov/phy2140/ Chapter 29 1 Lightning Review Last lecture: 1. Nuclear
More information9 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 informationChapter 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 informationCHARGED PARTICLE INTERACTIONS
CHARGED PARTICLE INTERACTIONS Background Charged Particles Heavy charged particles Charged particles with Mass > m e α, proton, deuteron, heavy ion (e.g., C +, Fe + ), fission fragment, muon, etc. α is
More informationStrand J. Atomic Structure. Unit 2. Radioactivity. Text
Strand J. Atomic Structure Unit 2. Radioactivity Contents Page Unstable Nuclei 2 Alpha, Beta and Gamma Radiation 5 Balancing Equations for Radioactive Decay 10 Half Life 12 J.2.1. Unstable Nuclei. The
More informationRadioactivity and energy levels
Radioactivity and energy levels Book page 497-503 Review of radioactivity β ; Free neutron proton β- decay is continuous β : Proton in nucleus neutron antineutrino neutrino Summary of useful equations
More informationAbsorption and Backscattering of β-rays
Experiment #54 Absorption and Backscattering of β-rays References 1. B. Brown, Experimental Nucleonics 2. I. Kaplan, Nuclear Physics 3. E. Segre, Experimental Nuclear Physics 4. R.D. Evans, The Atomic
More informationAbsorption 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 informationChapter 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 informationZX or X-A where X is chemical symbol of element. common unit: [unified mass unit = u] also known as [atomic mass unit = amu] or [Dalton = Da]
1 Part 5: Nuclear Physics 5.1. The Nucleus = atomic number = number of protons N = neutron number = number of neutrons = mass number = + N Representations: X or X- where X is chemical symbol of element
More informationPhysics 126 Practice Exam #4 Professor Siegel
Physics 126 Practice Exam #4 Professor Siegel Name: Lab Day: 1. Light is usually thought of as wave-like in nature and electrons as particle-like. In which one of the following instances does light behave
More informationLecture 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 informationLab 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 informationAbsorption and Backscattering ofβrays
Experiment #54 Absorption and Backscattering ofβrays References 1. B. Brown, Experimental Nucleonics 2. I. Kaplan, Nuclear Physics 3. E. Segre, Experimental Nuclear Physics 4. R.D. Evans, The Atomic Nucleus
More informationStudy Guide 7: Ionizing Radiation
Study Guide 7: Ionizing Radiation Text: Chapter 6, sections 1-11 (more than described in Study Guide), plus text 2.5 and lab manual section 7A-1 (on inverse-square law). Upcoming quizzes: Quiz 4 (final
More informationLab 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 informationRadiation 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 informationScintillation Detector
Scintillation Detector Introduction The detection of ionizing radiation by the scintillation light produced in certain materials is one of the oldest techniques on record. In Geiger and Marsden s famous
More informationL 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 informationWHAT 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 informationLifetime Measurement
Lifetime Measurement Calculator 3 The activity (in decays per second) of some radioactive samples varies in time in a particularly simple way. If the activity (R) in decays per second of a sample is proportional
More informationUnit 6 Modern Physics
Unit 6 Modern Physics Early Booklet E.C.: + 1 Unit 6 Hwk. Pts.: / 46 Unit 6 Lab Pts.: / 16 Late, Incomplete, No Work, No Units Fees? Y / N Essential Fundamentals of Modern Physics 1. A photon s energy
More informationRadiation 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 informationM1. (a) (i) cannot penetrate aluminium allow can only pass through air / paper too weak is neutral 1
M. (a) (i) cannot penetrate aluminium allow can only pass through air / paper too weak is neutral gamma rays not affected (by aluminium) allow all / most (gamma rays) to pass through too strong is neutral
More informationPhysics 3204 UNIT 3 Test Matter Energy Interface
Physics 3204 UNIT 3 Test Matter Energy Interface 2005 2006 Time: 60 minutes Total Value: 33 Marks Formulae and Constants v = f λ E = hf h f = E k + W 0 E = m c 2 p = h λ 1 A= A T 0 2 t 1 2 E k = ½ mv 2
More informationLABORATORY VIII NUCLEAR PHENOMENA
LABORATORY VIII NUCLEAR PHENOMENA Radioactive decay is the emission of particles such as photons, electrons, neutrons, or even other nuclei when atomic nuclei go from a high energy state to a lower energy
More informationAtomic Structure and Radioactivity
Atomic Structure and Radioactivity Models of the atom know: Plum pudding model of the atom and Rutherford and Marsden s alpha experiments, being able to explain why the evidence from the scattering experiment
More informationLECTURE 23 NUCLEI. Instructor: Kazumi Tolich
LECTURE 23 NUCLEI Instructor: Kazumi Tolich Lecture 23 2 Reading chapter 32.1 to 32.2 Nucleus Radioactivity Mass and energy 3 The famous equation by Einstein tells us that mass is a form of energy. E =
More informationChapter 44. Nuclear Structure
Chapter 44 Nuclear Structure Milestones in the Development of Nuclear Physics 1896: the birth of nuclear physics Becquerel discovered radioactivity in uranium compounds Rutherford showed the radiation
More informationNuclear Powe. Bronze Buddha at Hiroshima
Nuclear Powe Bronze Buddha at Hiroshima Nuclear Weapons Nuclear Power Is it Green & Safe? Nuclear Waste 250,000 tons of Spent Fuel 10,000 tons made per year Health Effects of Ionizing Radiation Radiocarbon
More informationGeneral Physics (PHY 2140)
General Physics (PHY 140) Lecture 18 Modern Physics Nuclear Physics Nuclear properties Binding energy Radioactivity The Decay Process Natural Radioactivity Last lecture: 1. Quantum physics Electron Clouds
More informationUnits and Definition
RADIATION SOURCES Units and Definition Activity (Radioactivity) Definition Activity: Rate of decay (transformation or disintegration) is described by its activity Activity = number of atoms that decay
More informationAtomic structure Radioactive decay Exponential functions and graphs
TEACHER NOTES LAB NR 4 RELATED TOPICS STANDARDS ADDRESSED Science and Technology 3.1.1, 3.1.1 3..1,3..1 3.4.1, 3.4.1 3.7.1, 3.7.1 3.8.1, 3.8.1 Atomic structure Radioactive decay Exponential functions and
More informationNice Try. Introduction: Development of Nuclear Physics 20/08/2010. Nuclear Binding, Radioactivity. SPH4UI Physics
SPH4UI Physics Modern understanding: the ``onion picture Nuclear Binding, Radioactivity Nucleus Protons tom and neutrons Let s see what s inside! 3 Nice Try Introduction: Development of Nuclear Physics
More informationLecture 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 informationPHYS 3650L - Modern Physics Laboratory
PHYS 3650L - Modern Physics Laboratory Laboratory Advanced Sheet Photon Attenuation 1. Objectives. The objectives of this laboratory exercise are: a. To measure the mass attenuation coefficient at a gamma
More informationIsotopes of an element have the same symbol and same atomic number - Mass number refers to the protons plus neutrons in an isotope
7.1 Atomic Theory and Radioactive Decay Natural background radiation exists all around us. This radiation consists of high energy particles or waves being emitted from a variety of materials Radioactivity
More informationThursday, April 23, 15. Nuclear Physics
Nuclear Physics Some Properties of Nuclei! All nuclei are composed of protons and neutrons! Exception is ordinary hydrogen with just a proton! The atomic number, Z, equals the number of protons in the
More informationChapter 18. Nuclear Chemistry
Chapter 18 Nuclear Chemistry The energy of the sun comes from nuclear reactions. Solar flares are an indication of fusion reactions occurring at a temperature of millions of degrees. Introduction to General,
More informationCHEMISTRY Topic #1: Atomic Structure and Nuclear Chemistry Fall 2017 Dr. Susan Findlay See Exercises 2.3 to 2.6
CHEMISTRY 1000 Topic #1: Atomic Structure and Nuclear Chemistry Fall 2017 Dr. Susan Findlay See Exercises 2.3 to 2.6 Balancing Nuclear Reactions mass number (A) atomic number (Z) 12 6 C In an ordinary
More informationNuclear Chemistry. Nuclear Terminology
Nuclear Chemistry Up to now, we have been concerned mainly with the electrons in the elements the nucleus has just been a positively charged things that attracts electrons The nucleus may also undergo
More informationPage 1. ConcepTest Clicker Questions Chapter 32. Physics, 4 th Edition James S. Walker
ConcepTest Clicker Questions Chapter 32 Physics, 4 th Edition James S. Walker There are 82 protons in a lead nucleus. Why doesn t the lead nucleus burst apart? Question 32.1 The Nucleus a) Coulomb repulsive
More informationYear 12 Notes Radioactivity 1/5
Year Notes Radioactivity /5 Radioactivity Stable and Unstable Nuclei Radioactivity is the spontaneous disintegration of certain nuclei, a random process in which particles and/or high-energy photons are
More informationProperties of the nucleus. 9.1 Nuclear Physics. Isotopes. Stable Nuclei. Size of the nucleus. Size of the nucleus
Properties of the nucleus 9. Nuclear Physics Properties of nuclei Binding Energy Radioactive decay Natural radioactivity Consists of protons and neutrons Z = no. of protons (tomic number) N = no. of neutrons
More informationThe interaction of radiation with matter
Basic Detection Techniques 2009-2010 http://www.astro.rug.nl/~peletier/detectiontechniques.html Detection of energetic particles and gamma rays The interaction of radiation with matter Peter Dendooven
More informationRadioactivity. (b) Fig shows two samples of the same radioactive substance. The substance emits β-particles. Fig. 12.1
112 (a) What is meant by radioactive decay? Radioactivity [2] (b) Fig. 12.1 shows two samples of the same radioactive substance. The substance emits β-particles. Fig. 12.1 Put a tick alongside any of the
More informationL 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