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1 Mass in grams Name: Date: Period: CP Chemistry Semester 1 Final Test Review CHAPTERS 1 & 2: Scientific Method, Density, Metric Conversions, Accuracy/Precision, Significant Figures 1. Know the steps in the scientific method. A. Define each of the steps. a) observation use of senses to obtain info about nature, b) hypothesis an educated guess, c) experimentation or testing a set of controlled experiments, d) collecting or recording data, e) drawing conclusions, f) theory, g) scientific law B. What is the difference between a theory and a scientific law? Scientific Law: Describes a relationship in nature that is supported by many experiments. Usually taken as fact by most scientists. Theory: An explanation supported by many experiments, but is still subject to new experimental data, and can be modified C. What is the difference between a hypothesis and a theory? Hypothesis: A tentative, testable statement or prediction about what has been observed. An educated guess. Theory: An explanation supported by many experiments, but is still subject to new experimental data, and can be modified 2. Know the symbol and the power of 10 for the following metric prefixes: A. Mega M 10 6 D. deka da 10 1 G. centi cm 10-2 B. kilo k 10 3 E. base (m, s, g) 10 0 H. milli m 10-3 C. hecto h 10 2 F. deci d 10-1 I. micro µ Metric Conversions: Give the value of the following in the units indicated. a cm = m b. 8 Mg = 8,000 kg c. 35 km = 3,500,000 cm d. 520 ml = 0.52 L e. 934 µm = mm f. 550 ml = 0.55 L g. 6,450,000 mg = _6.450_kg h g = 75 mg Density Problems: Calculate the following using correct units and significant digits. 4. A metal has a volume of 8.4 ml and a mass of 32.0 g. What is its density? 3.8 g/ml 5. A solid object has a density of 7.00 g/ml and a volume of 12.0 ml. What is its mass? 84.0 g 6. An object has a density of 9.0 g/ml and a mass of 41.2 g. What is its volume? 4.6 ml 7. Be able to read and interpret data off a line graph. MASS v. VOLUME FOR SAMPLES OF SUBSTANCE X a. If the mass is 30 grams, what is the volume? 15 ml b. What is the mass if you have 10 ml of substance X? 20 g c. Calculate the approximate slope of the line. y/ x Slope = (30-20)/(15-10) = 2 d. Calculate the approximate density of the substance X. density = slope of mass v. volume graph! = 2 g/ml (calculated in question c.) Volume in ml

8. Know the correct number of significant figures to report in calculations. Report these answers to the correct number of significant figures. A. 3.461 + 14.9 + 5.26331 = 23.6 (1 decimal place) B.

2 8. Know the correct number of significant figures to report in calculations. Report these answers to the correct number of significant figures. A = 23.6 (1 decimal place) B = 710 (2 sig figs) 9. Know the difference between Precision and Accuracy. Identify each of the targets to the right as ACCURATE and/or PRECISE. Accuracy: How closely individual measurements agree with the correct or true value Precision: How closely individual measurements agree (repeatibility) Left bullseye is neither precise nor accurate; middle is precise and accurate; right bullseye is precise but not accurate. CHAPTER 3: Matter: Physical and Chemical Changes 10. Explain the difference between a homogeneous mixture (solution) and a heterogeneous mixture. Give an example of each. Heterogeneous Mixture : A mixture that does not blend smoothly throughout ex. sand and water Homogeneous Mixture: A mixture that has constant composition throughout ex. salt and water 11. Explain the difference between a physical change and a chemical change. Give an example of each. Physical Change : A change in which no new substances are formed melting, boiling, distillation, crystallization, dissolving Chemical Change: New substances are formed combustion, burning, decomposition 12. Conservation of mass problems (mass of reactants = mass of products): a. Water is decomposed into hydrogen and oxygen. If 10.0 grams of hydrogen and 79.5 grams of oxygen are collected, how much water did you start with? 10.0 g hydrogen g oxygen = 89.5 g product = 89.5 g reactant (water) b. If 25 grams of sodium reacts with chlorine to form 99 grams of salt (NaCl). How many grams of chlorine reacted? Reactants: 25 g sodium + X g chlorine Products: 99 g salt (sodium chloride) 25 g + X g = 99 g X = 99 g -25 g = 74 g chlorine CHAPTERS 4 & 25: The Atom and Nuclear Chemistry 13. Which part of the atom has most of the mass but very little volume? The nucleus contains the protons and neutrons which make up most of the mass of the atom. The size of the nucleus is very small compared to the rest of the atom.

3 14. What are the charges and masses of protons, electrons, and neutrons? symbol mass (amu) charge proton p + 1 amu 1+ neutron n 0 1 amu 0 electron e - ~0 amu What are the differences in the atomic number, atomic mass and mass number? Atomic number Mass number Atomic mass Definition The number of protons in an element. It determines what element it is. In a neutral atom, atomic number also equals the number of electrons. ON THE PERIOIC TABLE. How to calculate # p + (or # e - in a neutral atom) The mass of a specific isotope p + + n 0 The weighted average mass of all naturally occurring isotopes. ON THE PERIODIC TABLE. 16. What is the definition of an isotope? An isotope is an element with different number of neutrons. Weighted average of mass number and percent abundance of all isotopes. 17. Why do isotopes of the same element (ex. carbon-12, carbon-13, carbon-14) have different mass numbers? Isotopes of the same element have different mass numbers because they have different numbers of neutrons (mass number = #p + + #n 0 ) 18. Which isotope is the standard for the atomic mass unit (amu)? 12 amu = mass of 1 carbon-12 atom (1 amu = 1/12 carbon-12 mass number) 19. Calculate the number of protons, neutrons and electrons in an isotope when given its mass number and atomic number. Element atomic number mass number protons neutrons electrons Isotope name (using name) Copper (Cu) Copper-64 Neon (Ne) Neon-21 Zinc (Zn) Zinc-65 Isotope name (using symbol) Magnesium (Mg) Magnesium- 26

4 20. In a chemical reaction, what changes in the atom and what is formed? Electrons are shared, gained or lost and a new compound is formed 21. In a nuclear reaction, what changes in the atom and what is formed? The nucleus of an atom changes and a new element is formed 22. Use the following data table on the isotopes of element X to answer Questions A&B listed below: Isotope Mass in amu Percent CALCULATE: Abundance % (Mass number) X (% abundance)/100 X X X Weighted average atomic mass (SUM OF CALCULATED VALUES): amu Weighted avg. atomic mass = (Mass x ) X-20 + (Mass x ) X-21 + (Mass x ) X-22 A. What is the weighted average atomic mass of element X? amu B. Using the periodic table what is the identity and atomic number of element X? Neon, Assume the following three isotopes of element Z exist: Z-248, Z-252, and Z-259. If the atomic mass of Z is amu, which of these isotopes is most abundant? Since the atomic mass is the weighted average, the most abundant will be the isotope with the mass number closest to the atomic mass: Z Why does radioactivity occur? Due to spontaneous decay of an unstable nucleus 25. Know that the forms of natural radioactivity are alpha, beta, and gamma. symbol Mass (amu) charge Damage caused Alpha α 4 2+ Stopped by clothing so no skin damage. Ingested or inhaled. Can cause lung cancer (i.e., radon gas) Beta β 0 1- Gamma γ 0 0 Can penetrate several mm into skin or be ingested by eating contaminated food. Can cause burns, tissue damage and radiation sickness. Can pass through your body. Causes cancer, radiation sickness, tissue and organ damage. 26. Which form of radiation has the lowest energy (ex. can be stopped by paper)? Alpha Which form has the highest energy (ex. will pass through several feet of concrete)? Gamma

5 27. What particles would you use to balance the following nuclear reactions? a. (a) (b) (c) b. (a) (b) (c) C. (a) (b) (c) 28. What is the difference between nuclear fusion and nuclear fission? In nuclear fusion, two smaller elements collide and form a larger element. In nuclear fission, a neutron hits a large nucleus and the nucleus splits into two smaller elements. 29. Identify the following as fission or fusion reactions and fill in the blank: A. + fusion B. fission 30. What is half life? Half life is the time it takes for half of a radioactive element to decay into another element. 31. Know how to solve half-life problems: Na- 24 has a half-life of 15 hours. How long will it take for a sample to decay to 12.5% of its original mass 100%/12.5% is 3 half lifes 3 x 15 hours = 45 hours 32. Write and balance the following equations: A. Radon-222 undergoes alpha decay (loses ) Radon Polonium-218 B. Uranium-238 undergoes beta decay Uranium Np -238 CHAPTER 5: Electrons in Atoms 33. Give the (1) electron configuration (2) noble gas shorthand and (3) orbital filling diagram for the following elements. a. Sulfur (atomic number 16) 1s 2 2s 2 2p 6 3s 2 3p 4 [Ne]3s 2 3p 4 1s 2s 2p 3s 3p b. Copper (atomic number 29) 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 9 [Ar]4s 2 3d 9 1s 2s 2p 3s 3p 4s 3d

6 34. Give the Lewis electron dot diagrams for the following elements. 35. Know how to convert between wavelength and frequency (c = 3.00 x 10 8 m/s). a. What is the wavelength of electromagnetic radiation having a frequency of Hz? c = λѵ λ = ( m/s) ( /s) λ = m b. What is the frequency of electromagnetic radiation having a wavelength of m? CHAPTER 6 The Periodic Table c = λѵ ѵ = ( m/s) ( m) ѵ = Hz or /s 36. Periodic Table Organization A. The periodic table is arranged by increasing atomic number. B. Rows on a periodic table are called periods. Columns on a periodic table are called groups or families. C. Properties of elements in the same (period or group) change as you move left to right or right to left and repeat as you move from one to the next. D. Properties of elements in a (period or group) are similar. E. All atoms of the same element contain the same number of what particle? Protons F. Identify the location of these groups or families: Alkali Metals (Group 1A) Alkaline Earth Metals (Group 2A) Halogens Group 7A) Noble Gases (Group 8A) G. Given the electron configuration, identify the element, period and group on the periodic table: [Ne]3s 2 3p 2 [Kr]5s 2 [Ne]3s 2 3p 6 [Ar] 4s 1 [Ne]3s 2 3p 5 Element Si Sr Ar K Cl Period Group 4A 2A alkaline earth metal 8A noble gases 1A alkali metals 7A halogens Metal/ nonmetal/ metalloid? Metalloid Metal Nonmetal Metal Nonmetal

electronegativity? Fluorine Which group/family has ZERO electronegativity?

7 Atomic Size and Ionic Size Electronegativity and Ionization Energy 37. Periodic Table Trends Know the definitions of each property and the general trends by group and period for: Electronegativity: Attraction of an atom for electrons Which element has the highest electronegativity? Fluorine Which group/family has ZERO electronegativity? Noble Gases Ionization Energy: Energy required to remove an electron from an atom Atomic Size (atomic radius): Distance between the center of an atom to the outer edge of the electron cloud (measured as half the distance between two nuclei) Ionic size (ion radius): Distance between the center of an ION (which has lost or gained electrons) to the outer edge of the electron cloud A. Identify which of the element in each pair has the LARGER atomic radius: a. K and Sc b. Cl and I c. Ca or Ga d. Se or O B. List the elements in order of INCREASING electronegativity: a. O, S, Se: Se, S, O b. Al, Cl, P: Al, P, Cl c. Ca, Mg, Sr: Sr, Ca, Mg Electronegativity and Ionization Energy Atomic Size and Ionic Size

8 CHAPTER 8 Ionic Compounds 38. An ion is an atom that has gained or lost electrons in order to become more stable; by achieving the noble gas configuration. 39. Complete the table for the ATOMS and IONS of these elements: Element Element Symbol Atomic Number # Valence Electrons in the Atom Total Number of Electrons in an Atom Total Number of Electrons in an Ion Ion symbol Magnesium Mg Mg 2+ Oxygen O O 2- Phosphorus P P 3- Aluminum Al Al 3+ Iodine I I - Lithium Li Li An ionic bond forms between what types of elements? A metal and a nonmetal An ionic bond is the attraction between positively charged metal cations and negatively charged anions. In an ionic bond, electrons are transferred from the metal (cation) to the nonmetal (anion). What is the structure of a solid ionic compound? Crystal lattice (alternating positive and negative ions packed closely together in a crystalline structure) What are properties of ionic compounds? Hard, brittle, very high melting points, can conduct electricity if dissolved in water or melted 41. A chemical formula tells you how many of each atom are in the compound, as indicated by subscripts. MgCl 2 means 1 magnesium and 2 chlorine atoms are in the compound. 42. Complete the tables below: Compound Name Chemical Formula Iron (III) Sulfate Fe 2 (SO 4 ) 3 Nickel (III) chloride NiCl 3 Aluminum Sulfide Al 2 S 3 Beryllium fluoride BeF What is the charge of the manganese ion in each of the compounds listed below? a. MnSO 3 B. MnPO 4 C. Mn 3 P 2 D. MnO 2 Mn SO 3 Mn PO 3 Mn 2+ P 3- Mn 4+ O 2-

CP Chemistry Semester 1 Final Test Review

Mass in grams 10 20 30 40 50 CP Chemistry Semester 1 Final Test Review 1. Know the symbol and the power of 10 for the following metric prefixes: A. Mega M 10 6 D. deka da 10 1 G. milli m 10 6 B. kilo k