AM 1 and AM 2 Review

1. The three basic components of an atom are:

(a) protons, neutrons, and ions(b) protons, neutrons, and electrons(c) protons, neutrinos, and ions(d) protium, deuterium, and tritium

Answer: b

2. The identity of an element is determined by the number of:

(a) atoms(b) electrons(c) neutrons(d) protons

Answer: d

3. The nucleus of an atom consists of:

(a) electrons(b) neutrons(c) protons and neutrons(d) protons, neutrons, and electrons

Answer: c

4. A single proton has what electrical charge?

(a) no charge(b) positive charge(c) negative charge(d) either a positive or negative charge

Answer: b

5. Which particles have approximately the same size and mass as each other?

(a) neutrons and electrons(b) electrons and protons(c) protons and neutrons(d) none - they are all very different in size and mass

Answer: c

6. Which two particles would be attracted to each other?

(a) electrons and neutrons(b) electrons and protons(c) protons and neutrons(d) all particles are attracted to each other

Answer: b

7. The atomic number of an atom is:

(a) the number of electrons(b) the number of neutrons(c) the number of protons(d) the number of protons plus the number of neutrons

Answer: c

8. Changing the number of neutrons of an atom changes its:

(a) isotope(b) element(c) ion(d) charge

Answer: a

9. When you change the number of electrons on an atom, you produce a different:

(a) isotope(b) ion(c) element(d) atomic mass

Answer: b

10. According to atomic theory, electrons are usually found:

(a) in the atomic nucleus(b) outside the nucleus, yet very near it because they are attracted to the protons(c) outside the nucleus and often far from it - most of an atom's volume is its electron cloud(d) either in the nucleus or around it - electrons are readily found anywhere in an atom

Answer: c

11. The spontaneous disintegration of unstable nuclei by the emission of particles is called

a. radioactivity

b. spontaneous combustion

c. chemical decomposition

Answer: a

12. An alpha particle has

a. 2 protons and 1 neutron

b. 2 protons and 2 neutrons

c. 1 proton and 2 neutrons

Answer: b

13. Fast moving electrons emitted by atomic nuclei are known as

a. alpha particles

b. beta particles

c. gamma rays

Answer: b

14. When radioactive decay changes atoms of one chemical element into atoms of another element, the process is called

a. nuclear explosions

b. chemical decomposition

c. transmutation

Answer: c

15. A thorium-232 atom undergoes alpha decay. What element will be the product of this process?

a. radium

b. uranium

c. plutonium

Answer: a

16. An atom of H-3 undergoes beta decay. The element that will be produced is

a. hydrogen

b. helium

c. lithium

Answer: b

17. The mass and charge of a gamma ray are

a. mass = 1 and charge = 0

b. mass = 0 and charge = 1

c. mass = 0 and charge = 0

Answer: c

18. An isotope having a half-life of 5 years currently has an average activity of 600 counts /min. What was the approximate activity of this sample 15 years ago?

Answer: 4800 counts/min.

19. The half-life of a radioactive isotope is 2.0 hours. If you start with an 80 gram sample, how much of the original isotope will remain after 10 hours?Answer: 2.5

grams

20. Balance the following

______ + 10n → 142

56Ba +9136Kr

+ 310n

23592U

21. Determine the number of protons and electrons in

the following ions

Ca +2

N -3

20 protons18 electrons

7 protons10 electrons