If you need scratch paper, use the back side of your scantron
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Chemistry (H): Unit 3 ‐ The Atom ‐ Test Multiple Choice Identify the choice that best completes the statement or answers the question.
1. The number of neutrons in a "normal" potassium atom is a. 125 d. 20 b. 16 e. none of the answers are correct c. 15
2. The atomic mass of manganese is a. 25 b. 54.94
c. d.
12 24.31
c. d.
A & C A & D
3. Which two atoms are isotopes of one another?
a. b.
A & B B & C
4. In Rutherford’s experiment, because a few particles fired at the gold foil bounced back from the foil, Rutherford concluded that they were a. striking electrons c. repelled by densely packed regions of postive charge b. indivisible d. magnetic
5. The number of electrons in 14C is a. 12 b. 14
6. An isotope is a. an atom with a different number of electrons b. an atom with a different number of protons
c. d.
12.011 6
c.
an atom with a different number of neutrons an atom with a different number of protons and neutrons
d.
7. Which of the following is NOT a part of Dalton’s Atomic Theory? a. All matter is composed of extremely c. In chemical reactions, atoms are small particles called atoms combined, separated, or rearranged b. Atoms of different elements combine in d. Atoms can be subdivided, created, or simple whole-number ratios destroyed
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ID: A
8. Which scientist described the atoms as “a positively charged core (nucleus) in the middle of a lot of empty space”? a. Chadwick c. Rutherford b. Thomson d. Bohr
9. Cobalt has an atomic mass of 59 and an atomic number of 27. What does this information reveal about most cobalt atoms? a. they contain more neutrons than c. they attract protons more strongly than protons electrons b. they naturally have a net negative charge d. they form ions with a charge of +27 in compounds
10. The atomic mass is a. the number of electrons in an atom b. the number of protons in an atom
c. d.
the number of neutrons in an atom the number of protons and neutrons in an atom
11. Which of the following statements applies to a nuclear fission reaction? a. the reaction has no commercial c. the reaction produces only short‐lived applications radioactive waste b. the reaction takes place only at very high d. the reaction releases large amounts of temperatures energy when nuclei split apart 12. Which is the correct symbol for the atom with 42 protons and 49 neutrons? a.
c.
b.
d.
13. If the particle that starts a nuclear reaction is also one of the products, the process is a a. chain reaction c. nuclear fusion b. neutron emission d. neutron bombardment 14. The number of electrons in 41Ca+2 is a. 2 b. 18
c. d.
20 22
15. Which of the following statements best describes a difference between nuclear fission and nuclear fusion reactions? a. nuclei split during fission and combine c. fission generates potential energy, and during fusion fusion generates kinetic energy b. fission forms heavier elements, and d. nuclei gain electrons during fission and fusion forms lighter elements release electrons during fusion
2
ID: A
16. An electron a. has a negative charge and is located in the nucleus b. has a postive charge and is located in the nucleus 17. The atomic number a. is the number of electrons in an atom b. is the number of protons in an atom c. is the number of neutrons in an atom 18. The number of neutrons in 36S is a. 36 b. 16
c. d.
has a postive charge and circles around the nucleus has a negative charge and circles around the nucleus
d. e.
none are correct more than one answer is correct
c. d.
20 32.07
19. Mass defect is the difference betweent he mass of a. a nucleus and its atom c. an atom and the sum of the masses of its electrons b. a neutron and a proton d. an atom and the sum of the masses of its constituent particles 20. Which scientist developed the theory that an atom looked like “plum pudding”?
a. b.
Chadwick Thomson
c. d.
Rutherford Bohr
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ID: A
21. Which is the correct symbol for the following atom?
a.
c.
b.
d.
22. The half‐life of an isotope is the time required for half the nuclei in a sample to a. undergo radioactive decay c. undergo nuclear fusion b. undergo nuclear fission d. react chemically 23. Which type of nuclear radiation can be blocked by a piece of paper? a. alpha c. gamma b. beta d. none can be blocked by paper 24. Which of the following lists ranks nuclear radiation from most massive (size wise) to least massive? a. alpha, beta, gamma c. gamma, alpha, beta b. beta, gamma, alpha d. gamma, beta, alpha 25. An industrially important element contains 26 electrons and rusts in the presence of air and moisture. Identify the element. a. Aluminum c. Potassium b. Iron d. Sodium 26. The fact that a chemical compound contains the same elements in exactly the same proportions by mass regardless of the size of the sample or source of the compound is known as the a. law of multiple proportions c. law of determining proportions b. law of definite proportions d. law of conservation of mass 27. The atomic theories of Dalton, Thomson, Rutherford, and Bohr all support which of the following statements? a. atoms are mostly composed of empty c. electrons orbit the nucleas of an atom at space distinct energy levels b. all matter is composed of tiny, discrete d. atoms are composed of positively and particles called atoms negatively charged particles
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Matching
28. Where are the electrons located? 29. Where are the neutrons located? 30. Where are the protons located?
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Chemistry (H): Unit 3 ‐ The Atom ‐ Test Answer Section MULTIPLE CHOICE
