Name Honors Chemistry: Atoms, protons, electrons, neutrons, and the Periodic Table

Transcription

1 Name Honors Chemistry: Atoms, protons, electrons, neutrons, and the Periodic Table 1. In the Periodic Table below, draw or shade in the following a. the numbers for the 8 main groups (also, indicate the charge members of that these families are most likely to have) b. the alkali metals c. the alkaline earth metals d. the stair-step separating metals from nonmetals (be sure you know which side is metal, which side is nonmetal) e. the halogens f. the noble gases g. the transition elements h. period (row) 4 i. the s block j. the p block k. the d block l. the f block 2. While the Periodic Table is not something that a student memorizes, it is something that you'll gain familiarity with over time. To see what you know right now, see if you can place the following elements in the their correct locations on the blank table below. Na, F, C, He, Mg, N, S, O, Al, Fe, Li, K, Ca, P, Cl, I, Fr, Br, Kr, Zn, Au

2 3. Complete the following table Name or Symbol Z A neutrons gallium-70 chlorine-36 protons 8 15 Mg copper-65 N Sr S 2- electrons 4. Gallium occurs in nature as a mixture of two isotopes. They are Ga-69 with % abundance and a mass of amu and Ga-71 with a % abundance and an atomic mass of Calculate the atomic mass of gallium. 5. The element chlorine occurs in nature as a mixture of two isotopes. Chlorine-35 has a atomic mass of amu and makes up 75.77% of chlorine atoms. Chlorine-37 atoms make up the remaining 24.23% of all chlorine. Use the average atomic mass of chlorine from the periodic table to calculate the atomic mass of Cl-37 atoms. 6. Copper exists as a mixture of two isotopes. The lighter isotope (Cu-63), with 29 protons and 34 neutrons, makes up 69.17% of copper atoms. The heavier isotope (Cu-65), with 29 protons and 36 neutrons, constitutes the remaining 30.83% of copper atroms. The atomic mass of Cu-63 is amu, and the atomic mass of Cu-65 is amu. Compute the atomic mass of copper. Multiple Choice and Short Answer 1. Which of the following from John Dalton s Model was later proven wrong? a) All matter is composed of indivisible atoms. b) An element is composed of only one type of atom. c) Two or more elements combine to form compounds. d) A chemical reaction only involves the separation, combination, or rearrangement of atoms NOT the creation or destruction of atoms. 2. A compound always has the same elements in the same proportion by mass. This is the. a) law of conservation of mass b) law of multiple proportions c) law of definite proportions d) law of constant proportions 3. Which of the following statements is true? a) J.J. Thomson carried out experiments with cathode rays that led to the discovery of the proton. b) Eugene Goldstein carried out experiments with canal rays that led to the discovery of the neutron. c) James Chadwick won the Nobel Prize for the discovery of the electron. d) Ernest Rutherford s Alpha-Scattering Experiment led to the discovery of the atomic nucleus.

3 4. Check all the discoveries below that resulted from Rutherford s Alpha-Scattering Experiment: a) Protons are positively charged. b) Electrons are negatively charged. c) The atom is mostly empty space. d) Protons are concentrated in the nucleus of the atom. e) the relative size of the atom and its nucleus 5. Check all of the statements below that are true: a) Protons have a +1 charge. b) Electrons have no charge. c) Protons and neutrons are located inside the nucleus. d) Almost all of the mass of an atom comes from the protons and neutrons. e) Isotopes vary in the protons. f) In a neutral atom, the protons equals the electrons. 6. The number is the whole protons equal to the whole electrons in a neutral atom. 7. How many protons, neutrons, and electrons are present in cobalt-60? 8. How many protons, neutrons, and electrons are present in silicon-29? 9. How many protons, neutrons, and electrons are present in chlorine-37? 10. How many protons, neutrons, and electrons are present in magnesium-26? 11. Isotopes vary in their. a) protons b) neutrons c) electrons d) atomic number e) element symbol 12. Use the atomic weight reported on the Periodic Table to determine the most abundant naturally occurring element for potassium: a) potassium-39 b) potassium-40 c) potassium Use the atomic weight reported on the Periodic Table to determine the most abundant naturally occurring element for copper (Cu): a) copper-63 b) copper Use the atomic weight reported on the Periodic Table to determine the most abundant naturally occurring element for iron (Fe): a) iron-54 b) iron-56 c) iron-57 d) iron An element has two naturally occurring isotopes with the following masses and relative abundances: Isotopic Mass (amu) Fractional Abundance What is the atomic weight of this element? Report your answer with the correct units and the significant figures.

4 16. Use the Periodic Table and the atomic weight you calculated to identify the element in problem #15 above. Give either the element name or the element symbol. 17. An element has three naturally occurring isotopes with the following masses and relative abundances: Isotopic Mass (amu) Fractional Abundance What is the atomic weight of this element? Report your answer with the correct units and the significant figures. 19. Use the Periodic Table and the atomic weight you calculated to identify the element in problem #17 above. Give either the element name or the element symbol. 20. True or False: There is an isotope of carbon with a mass Explain your answer.

5 Some Answers 3. Complete the following table Name or Symbol Z A neutrons protons electrons gallium chlorine oxygen Mg copper N Se tin Sr S amu amu amu MC + short answer 1. a 2. c 3. d 4. a, c 5. a, c, d, f 6. atomic number protons, 33 neutrons, 27 electrons protons, 15 neutrons, 14 electrons protons, 20 neutrons, 17 electrons protons, 14 neutrons, 12 electrons 11. b 12. a 13. a 14. b 15., amu, Rb , Si 20. False. Mass number (A) must be an integer no fractions.