Download Atomic Structure Practice Test Multiple Choice Identify the choice

Atomic Structure Practice Test
Multiple Choice Identify the choice that best completes the statement or answers the question.
____
1. Whose series of experiments identified the nucleus of the atom?
a. Rutherford
b. Dalton
c. Chadwick
d. Bohr
____
2. A nuclear particle that has about the same mass as a neutron, but with a positive charge, is called a(n)
a. proton.
b. neutron.
c. electron.
d. isotope.
____
3. Which part of an atom has a mass approximately equal to 1/2000 of the mass of a proton or a neutron?
a. nucleus
b. electron
c. proton
d. neutron
____
4. The atomic number of chlorine, 17, indicates that there are seventeen
a. protons in the nucleus.
c. neutrons outside the nucleus.
b. chlorine nuclides.
d. energy levels in the nucleus.
____
5. The total number of protons and neutrons in the nucleus of an atom is its
a. atomic number.
b. atomic weight.
c. mass number.
d. atomic mass.
____
6. All atoms of the same element have the same
a. atomic mass.
b. # of neutrons.
c. mass number.
7. The average atomic mass of an element
a. is the mass of the most abundant isotope.
b. may not equal the mass of any isotopes.
c. cannot be calculated.
d. always adds up to 100.
8. Polonium-210 has
a. 210 neutrons.
b. 84 neutrons.
c. 126 neutrons.
d. 105 neutrons.
9. Argon-38 contains
a. 38 protons.
b. 20 protons.
c. 33 neutrons.
d. 18 protons.
____
____
____
d. atomic number.
____ 10. When 999/1000 alpha particles passed through the gold foil, this told Rutherford that
a. an atom is mostly b. an atom has a
c. the nucleus has a d. the matter in an
empty space.
nucleus.
positive charge.
atom’s very dense.
____ 11. 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
____ 12. According to Dalton's atomic theory, atoms
a. are destroyed in chemical reactions.
b. can be divided.
c. of each element are identical in size, mass, and other properties.
d. of different elements cannot combine.
____ 13. Which of the following statements is true according to modern atomic theory?
a. Atoms of the same element may have different masses.
b. Atoms may be divided in ordinary chemical reactions.
c. Atoms can never combine with any other atoms.
d. Cathode rays are composed of protons..
____ 14. When the light from electrified atoms was passed through a prism in Niels Bohr’s experiment,
a. he saw the whole spectrum of colors.
c. he saw electrons jumping to higher levels.
b. he saw narrow bands of a few colors.
d. he saw white light.
____ 15. Thomson’s experiments with cathode rays led to the discovery of the
a. proton
b. nucleus.
c. neutron.
d. electron.
____ 16. Because any element used in the cathode produced electrons, scientists concluded that
a. all atoms contained electrons.
c. atoms were indivisible.
b. only metals contained electrons.
d. atoms carried a negative charge.
____ 17. If you change the number of protons in an atom, what is affected?
a. The mass of the atom
c. The charge on the atom
b. The identity of the atom
d. All choices are correct
____ 18. Because a few alpha particles bounced back from the foil, Rutherford concluded that they were
a. striking electrons.
b. indivisible.
c. repelled by densely packed regions of positive charge.
d. magnetic.
____ 19. The nucleus of an atom has all of the following characteristics except that it
a. is positively charged.
b. is very dense.
c. contains nearly all of the atom's mass.
d. contains nearly all of the atom's volume.
____ 20. An atom is electrically neutral because
a. neutrons balance the protons and electrons.
b. nuclear forces stabilize the charges.
c. the numbers of protons and electrons are equal.
d. the numbers of protons and neutrons are equal.
____ 21. Isotopes are atoms of the same element that have different
a. principal chemical properties.
c. numbers of protons.
b. masses.
d. numbers of electrons.
____ 22. As the atomic number increases, the number of electrons in a neutral atom
a. decreases.
c. remains the same.
b. increases.
d. is undetermined.
____ 23. In determining the atomic mass of elements, the standard is the
a. C-12 atom.
b. C-14 atom.
c. H-1 atom.
d. O-16 atom.
____ 24. The average atomic mass of an element is the average of the atomic masses of its
a. naturally occurring isotopes.
c. radioactive isotopes.
b. two most abundant isotopes.
d. artificial isotopes.
____ 25. Chlorine has atomic number 17 and mass number 35. It has
a. 17 protons, 17 electrons, and 18 neutrons.
b. 35 protons, 35 electrons, and 17 neutrons.
c. 17 protons, 17 electrons, and 52 neutrons.
d. 18 protons, 18 electrons, and 17 neutrons.
____ 26. Neon-22 contains 12 neutrons. It also contains
a. 12 protons.
b. 22 protons.
c. 22 electrons.
d. 10 protons.
Short Answer/Problem
27. Using the data below, calculate the atomic mass of nitrogen.
isotope
Nitrogen
14
7N
15
7N
% abundance
99.63
0.37
mass
14.003
15.000
28. What is the relationship between isotopes, mass number, and neutrons?
Essay
29. Why do scientists use Dalton's theory, even though parts of it have been proven wrong? Which parts of
Dalton’s theory have been changed?
30. There are two isotopes of chlorine: chlorine-35 and chlorine-37. If the atomic mass of chlorine is 35.45, what
can you conclude about the abundance of each isotope?
Atomic Structure Test
Answer Section
MULTIPLE CHOICE
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
A
A
B
A
C
D
B
C
D
A
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
1
1
1
1
1
1
1
1
1
DIF:
DIF:
DIF:
DIF:
DIF:
DIF:
DIF:
DIF:
DIF:
I
I
I
II
I
I
I
III
III
REF:
REF:
REF:
REF:
REF:
REF:
REF:
REF:
REF:
2
2
2
3
3
3
3
3
3
11.
12.
13.
14.
15.
16.
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
OBJ:
ANS:
OBJ:
ANS:
OBJ:
ANS:
OBJ:
ANS:
OBJ:
ANS:
OBJ:
ANS:
OBJ:
ANS:
OBJ:
ANS:
OBJ:
ANS:
OBJ:
ANS:
OBJ:
A
C
A
B
D
A
1
D
2
C
2
D
3
C
3
B
1
B
2
A
2
A
2
A
3
D
3
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
STA:
PTS:
STA:
PTS:
STA:
PTS:
STA:
PTS:
STA:
PTS:
STA:
PTS:
STA:
PTS:
STA:
PTS:
STA:
PTS:
STA:
PTS:
STA:
1
1
1
1
1
1
SC.A.2.4.1
1
SC.A.2.4.1
1
SC.A.2.4.1
1
SC.C.2.4.2
1
SC.C.2.4.2
1
SC.A.2.4.3
1
SC.A.2.4.3
1
SC.A.2.4.3
1
SC.A.2.4.3
1
SC.A.2.4.1
1
SC.A.2.4.1
DIF:
DIF:
DIF:
DIF:
DIF:
DIF:
II
I
II
I
I
I
REF:
REF:
REF:
REF:
REF:
REF:
1
1
1
1
2
2
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
SHORT ANSWER
DIF: I
REF: 2
DIF: I
REF: 2
DIF: II
REF: 2
DIF: I
REF: 2
DIF: I
REF: 3
DIF: I
REF: 3
DIF: I
REF: 3
DIF: I
REF: 3
DIF: III
REF: 3
DIF: III
REF: 3
27. ANS:
99.63
0.37
14.003
15.000
0.9963 x 14.003 amu = 13.9511889
0.0037 x 15.000 amu = 0.0555
14.0066889
ROUND TO 5 SF = 14.007 amu
28. ANS: Isotopes are atoms of the same element with different numbers of neutrons, and therefore, different
mass numbers.
29. ANS: Even though we know that atoms of the same element are NOT identical b/c of the existence of
isotopes, and even though we know that atoms ARE divisible, Dalton was the first to put together a cohesive
theory that explained with a large degree of success the behavior of atoms and their relationships to one
another. In addition, most of his principles are still utilized in today’s atomic theory.
30. ANS: chlorine-35 is in greater abundance because the average mass is closer to 35 amu than to 36 amu.