Regents Review
Atom Worksheet
Mr. Beauchamp
1. Which subatomic particles are located in the nucleus of a neon
atom?
A. electrons and positrons
C. protons and neutrons
B. electrons and neutrons
D. protons and electrons
8. What is the net charge on an ion that has 9 protons, 11
neutrons, and 10 electrons?
A. 1+
C. 1‚
B. 2+
D. 2‚
2. Which statement best describes the nucleus of an aluminum
atom?
A. It has a charge of +13 and is surrounded by a total of 10
electrons.
B. It has a charge of + 13 and is surrounded by a total of 13
electrons.
C. It has a charge of -13 and is surrounded by a total of 10
electrons.
D. It has a charge of -13 and is surrounded by a total of 13
electrons.
9. What is the t otal charge of the nucleus of a carbon atom?
A. –6
C. +6
B. 0
D. +12
10. Which notation represents an atom of sodium with an atomic
number of 11 and a mass number of 24?
A. 24
C. 13
11 Na
11 Na
3. Which statement concerning elements i s true?
A. Different elements must have different numbers of
isotopes.
B. Different elements must have different numbers of
neutrons.
C. All atoms of a given element must have the same mass
number.
D. All atoms of a given element must have the same atomic
number.
12. Which subatomic particle has a negative charge?
A. proton
C. neutron
B. electron
D. positron
B.
A.
B.
C.
D.
D.
15. Which two particles make up most of the mass of a hydrogen-2
atom?
A. electron and neutron
C. proton and neutron
B. electron and proton
D. proton and positron
16. Which two particles each have a mass approximately equal to
one atomic mass unit?
A. electron and neutron
C. proton and electron
B. electron and positron
D. proton and neutron
An atom is mainly empty space, and t he nucleus has a
positive charge.
An atom is mainly empty space, and t he nucleus has a
negative charge.
An atom has hardly any empty space, and the nucleus has a
positive charge.
An atom has hardly any empty space, and the nucleus has a
negative charge.
7. Subatomic particles can usually pass undeflected through an
atom because the volume of an atom is composed of
A. an uncharged nucleus
C. neutrons
B. largely empty space
D. protons
a greater quant ity of charge and the same si gn
a greater quant ity of charge and the opposite sign
the same quanti ty of charge and the same si gn
the same quant ity of charge and the opposite sign
14. How many electrons are in an Fe 2+ ion
A. 24
C. 28
B. 26
D. 56
6. Which conclusion is based on the “ gold foil experiment” and
the resul ting model of the atom?
C.
35
11 Na
13. Compared to a proton, an electron has
5. Which sequence represents a correct order of historical
developments leading to the modern model of the atom?
A. the atom is a hard sphere → most of the atom is empty
space → electrons exist in orbitals outside the nucleus
B. the atom is a hard sphere → electrons exist in orbitals
outside the nucleus → most of the atom is empty space
C. most of the atom is empty space → electrons exist in
orbitals outside the nucleus → the atom is a hard sphere
D. most of the atom is empty space → the atom is a hard
sphere → electrons exist in orbitals outside the nucleus
B.
D.
11. Compared to an atom of phosphorus-31, an atom of sulfur-32
contains
A. one less neutron
C. one more neutron
B. one less proton
D. one more proton
4. What are the characteristics of a neutron?
A. It has no charge and no mass.
B. It has no charge and a mass of 1 amu.
C. It has a charge of +1 and no mass.
D. It has a charge of +l and a mass of 1 amu.
A.
11
24 Na
17. What is the mass number of an atom that has six protons, six
electrons, and eight neutrons?
A. 6
C. 14
B. 12
D. 20
18. What is the total number of neutrons in the nucleus of a neutral
atom that has 19 electrons and a mass number of 39?
A. 19
C. 39
B. 20
D. 58
19. In which list are the elements arr anged in order of increasing
atomic mass?
A. Cl, K, Ar
C. Te, I, Xe
B. Fe, Co, Ni
D. Ne, F, Na
Page 1
Atom Worksheet
20. A student constructs a model for comparing the masses of
subatomic particles. The student selects a small, metal sphere
with a mass of 1 gram to represent an electron. A sphere with
which mass would be mo st appropri ate to represent a proton?
1
A. 1g
C. 12000
g
1
B. 2 g
D. 2000 g
30. The atomic mass of an element is the weighted average of the
A. number of protons in the isotopes of that element
B. number of neutrons in the isotopes of that element
C. atomic numbers of the natural ly occurring isotopes of that
element
D. atomic masses of the natural ly occurring isotopes of that
element
1
21. The mass of an electron is approximately equal to 11836
of the
mass of
A. a positron
C. an alpha particle
B. a proton
D. a beta particle
22. Atoms of different isotopes of the same element differ in the ir
total number of
A. electrons
C. protons
B. neutrons
D. valence electrons
23. The nucleus of an atom of cobalt-58 contains
A. 27 protons and 31 neutrons
B. 27 protons and 32 neutrons
C. 59 protons and 60 neutrons
D. 60 protons and 60 neutrons
25. Isotopes of an element must have different
A. atomic numbers
C. numbers of protons
B. mass numbers
D. numbers of electrons
26. What is the total number of neutrons in an at om of an element
that has a mass number of 19 and an atomic number of 9?
9
10
C.
D.
32. In a calcium atom in the ground state, t he electrons that possess
the least amount of energy are located in the
A. first electron shell
C. third electron shell
B. second electron shell
D. fourth electron shell
33. How do the energy and the most probable location of an
electron in the th ird shel l of an atom compare to the energy and
the most probable location of an electron in the first shell of the
same atom?
A. In the third shell, an electron has more energy and is clo ser
to the nucleus.
B. In the third shell, an electron has more energy and is
farther from the nucleus.
C. In the third shell, an el ectron has less energy and is closer
to the nucleus.
D. In the third shell, an electron has less ener gy and is farther
from the nucleus.
24. The stabili ty of an isotope is based on its
A. number of neutrons, only
B. number of protons, only
C. ratio of neutrons to protons
D. ratio of electrons to protons
A.
B.
31. Compared to an electron in the first electron shell of an atom,
an electron in the third shel l of the same atom has
A. less mass
C. more mass
B. less energy
D. more energy
19
28
34. Which electron config uration could represent a strontium at om
in an excited state?
A. 2–8–18–7–1
C. 2–8–18–8–1
B. 2–8–18–7–3
D. 2–8–18–8–2
35. An electron in an atom moves from the ground state to an
excited stat e when the energy of the electron
27. Which isotopic notation represents a n atom of carbon-14?
A. 68C
C. 614C
B. 86C
D. 14
6 C
A.
B.
decreases
increases
C.
remains the same
36. As an electron in an atom moves from the ground state to the
excited state, the electron
A. gains energy as it moves to a higher ener gy level
B. gains ener gy as it moves to a lower energy level
C. loses ener gy as it moves to a higher energy level
D. loses ener gy as it moves to a lower energy level
28. A 100.00-gram sample of naturall y occurring boron contains
19.78 grams of boron-10 (atomic mass = 10.01 atomic mass
units) an d 80.22 grams of boron- 11 (at omic mass = 11.01
atomic mass units). Which numerical setup can be used to
determine t he atomic mass of naturall y occurring boron?
A. (0.1978)(10.01) + (0.8022)(11.01)
B. (0.8022)(10.01) + (0.1978)(11.01)
C. (0.1978)(10.01)/(0.8022)(11.01)
D. (0.8022)(10.01)/(0.1978)(11.01)
29. The atomic mass of element A is 63.6 atomic mass units. The
only naturally occurring isotopes of ele ment A are A-63 and
A-65. The percent abundances in a na turally occurring sample
of element A are closest to
A. 31% A-63 and 69% A-65 C. 69% A-63 and 31% A-65
B. 50% A-63 and 50% A-65 D. 100% A-63 and 0% A-65
37. An atom of oxygen is in a n excited sta te. When an el ectron in
this atom moves from the third shell to the second shell, energy
is
A. emitted by the nucleus
C. absorbed by the nucleus
B. emitted by the electron
D. absorbed by the electron
38. According to the wave-mechanical model of the at om, electrons
in an atom
A. travel in defined circles
B. are most likely found in an excited state
C. have a positive charge
D. are located in orbitals outside the nucleus
Page 2
Atom Worksheet
39. Which group of atomic models is liste d in hist orical order from
the earliest t o the most recent?
A. hard-sphere model, wave-mechanical model, electron-shell
model
B. hard-sphere model, electron-shell model, wave-mec hanical
model
C. electron-shell model, wave-mechanical model, hard-sphere
model
D. electron-shell model, hard-spher e model, wave-mechanic al
model
40. Which electron conf iguration represe nts an atom of lithium in
an excited state?
A. 1s12s1
C. 1s22s1
1 2
B. 1s 2s
D. 1s22s2
Page 3
Atom Worksheet
Answer Key
1.
C
31.
D
2.
B
32.
A
3.
D
33.
B
4.
B
34.
B
5.
A
35.
B
6.
A
36.
A
7.
B
37.
B
8.
C
38.
D
9.
C
39.
B
40.
B
10.
A
11.
D
12.
B
13.
D
14.
A
15.
C
16.
D
17.
C
18.
B
19.
A
20.
D
21.
B
22.
B
23.
A
24.
C
25.
B
26.
B
27.
D
28.
A
29.
C
30.
D