Unit 3 Test
1. A particle of matter contains 6 protons,
7 neutrons, and 6 electrons. This
particle must be a
A |
neutral nitrogen atom |
C |
positively charged
carbon ion |
B |
neutral carbon atom |
D |
positively charged
nitrogen ion |
2. The mass number of an atom is always
equal to the total number of its
A |
protons only |
C |
electrons plus
protons |
B |
electrons only |
D |
protons plus neutrons |
3. What is the approximate mass of an
electron?
A |
1 atomic mass unit |
C |
1/1836 of
a proton |
B |
1/12 of a
C-12 atom |
D |
1836/1837 of a
proton |
4. What is the molar mass of calcium
nitrate, Ca(NO3)2?
A |
164 g/mole |
C |
102 g/mole |
B |
150. g/mole |
D |
70.0 g/mole |
5. What is the total number of atoms in 1
mole of calcium?
A |
1 |
C |
6.02 x 1023 |
B |
40 |
D |
40(6.02 x 1023) |
6. What is the mass (in grams) of 3.0 x 1023
molecules of CO2?
A |
22 g |
B |
44 g |
C |
66 g |
D |
88 g |
7. The major portion of an atom’s mass
consists of
A |
electrons and protons |
C |
neutrons and
positrons |
B |
electrons and
neutrons |
D |
neutrons and protons |
8. Which atom contains exactly 15 protons?
A |
phosphorus - 32 |
C |
oxygen - 15 |
B |
sulfur - 32 |
D |
nitrogen - 15 |
9. Which symbols represent atoms that are
isotopes of each other?
A |
14C and 14N |
B |
131I and 131I |
C |
16O and 18O |
D |
222Rn and 222Ra |
10. Which pair of atoms contains the same number of
neutrons?
A |
11H and 32He |
B |
31H and 32He |
C |
21H and 42He |
D |
31H and 42He |
11. The atomic theory proposed by
A |
has been totally
discarded |
C |
has been accepted
unchanged to the present day |
B |
has been expanded and modified |
D |
has been found to be
false |
12. As the average atomic masses of the elements on
the Periodic Table increase, the number of atoms in 1 mole of each element
A |
decreases |
B |
increases |
C |
remains the same |
13.
A |
could not combine |
C |
all had the same mass |
B |
could not be created or destroyed |
D |
were invisible |
14. Element X has two naturally-occurring
isotopes. If the percent abundance of 85X
is 72.0% and the percent abundance of 87X is 28.0 %, the average
atomic mass of element X is equal to
A |
(72.0 x 85) x (28.0 +
87) |
C |
(0.72 x 87) + (0.28 x
85) |
B |
(72.0 - 85) x (28.0 +
87) |
D |
(0.72 x 85) + (0.28 x 87) |
15. How many neutrons does fluorine - 17 have in
its nucleus?
A |
9 |
B |
8 |
C |
7 |
D |
6 |
16. Most of the volume of an atom is made up of the
A |
nucleus |
B |
electron cloud |
C |
neutrons |
D |
protons |
17. The atomic number of neon is 10. The atomic number of calcium is 20. Compared with a mole of neon, a mole of
calcium contains
A |
twice as many atoms |
C |
an equal number of atoms |
B |
half as many atoms |
D |
20 times as many
atoms |
18. The nucleus of an atom has all of the following
characteristics EXCEPT that it
A |
is positively charged |
C |
contains nearly all
of the atom’s mass |
B |
is very dense |
D |
contains nearly all of the atom’s volume |
19. Zinc - 66 (atomic number 30) has
A |
30 neutrons |
B |
35 neutrons |
C |
36 neutrons |
D |
96 neutrons |
20. The atomic number of oxygen, 8, indicates that
there are eight
A |
protons in the nucleus of an oxygen atom |
B |
oxygen isotopes |
C |
neutrons outside the
oxygen atom’s nucleus |
D |
energy levels in the
oxygen atom’s nucleus |
21. An aluminum isotope consists of 13 protons, 13
electrons, and 14 neutrons. Its mass
number is
A |
13 |
B |
14 |
C |
27 |
D |
40 |
22. The mass of 2.50 moles of calcium atoms is
approximately
A |
10.0 g |
B |
100. g |
C |
42.5 g |
D |
250. g |
23. What is the correct number of atomic particles in
a neutral atom with an atomic number of 53 and a mass number of 127?
A |
protons = 53,
electrons = 127, neutrons = 127 |
B |
protons = 53,
electrons = 74, neutrons = 74 |
C |
protons = 127,
electrons = 127, neutrons = 74 |
D |
protons = 53, electrons = 53, neutrons = 74 |
24. According to the law of conservation of mass,
when sodium, hydrogen, and oxygen react to form a compound, the mass of the
compound is ___ the sum of the masses of the individual elements.
A |
equal to |
C |
less than |
B |
greater than |
D |
either greater than
or less than |
25. An ion with 5 protons, 6 neutrons, and a charge
of +3 has an atomic number of
A |
5 |
B |
6 |
C |
8 |
D |
11 |
Matching
Match the scientist to his
contribution to the development of the atomic theory.
A |
Bohr |
D |
|
B |
Chadwick |
E |
Thomson |
C |
|
|
26. discovered the neutron B
27. discovered the electron using a
cathode ray tube E
28. postulated that electrons travel
around the nucleus in orbits A
29. first published atomic theory; law of conservation of mass C
30.
discovered the nucleus using the gold foil experiment D