Download Atomic Structure Practice Test

Atomic Structure Practice Test
Multiple Choice Identify the choice that best completes the statement or answers the question.
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1. If 6.0 g of element K combine with 17 g of element L, how many grams of element K combine with 85 g of
element L?
a. 17 g
b. 23 g
c. 30. g
d. 91 g
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2. Which of the following is not part of Dalton's atomic theory?
a. Atoms cannot be divided, created, or destroyed.
b. The number of protons in an atom is its atomic number.
c. In chemical reactions, atoms are combined, separated, or rearranged.
d. All matter is composed of extremely small particles called atoms.
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3. Dalton's atomic theory agrees with modern atomic theory except for the statement that
a. all matter is made up of small particles.
b. atoms are not divided in chemical reactions.
c. atoms of the same element are chemically alike.
d. all atoms of the same element have the same mass.
____
4. The rays produced in a cathode tube are
a. unaffected by a magnetic field.
b. deflected away from a negative plate.
c. found to carry a positive charge.
d. striking the cathode.
____
5. After measuring the ratio of the charge of a cathode-ray particle to its mass, Thomson concluded that the
particles
a. had no mass.
c. had a very large mass.
b. had a very small mass.
d. carried a positive charge.
____
6. Whose series of experiments identified the nucleus of the atom?
a. Rutherford
b. Dalton
c. Chadwick
d. Bohr
____
7. Because most particles fired at metal foil passed straight through, Rutherford concluded that
a. atoms were mostly empty space.
c. electrons formed the nucleus.
b. atoms contained no charged particles.
d. atoms were indivisible.
____
8. A nuclear particle that has about the same mass as a proton, but with no electrical charge, is called a(n)
a. nuclide.
b. neutron.
c. electron.
d. isotope.
____
9. 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
____ 10. The smallest unit of an element that can exist either alone or in combination with other such particles of the
same or different elements is the
a. electron.
b. proton.
c. neutron.
d. atom.
____ 11. The atomic number of oxygen, 8, indicates that there are eight
a. protons in the nucleus.
c. neutrons outside the nucleus.
b. oxygen nuclides.
d. energy levels in the nucleus.
____ 12. 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.
____ 13. As the mass number of an element’s isotopes of an element increases, the number of protons
a. decreases.
b. increases.
c. remains the same.
d. doubles each time the mass number increases.
____ 14. All atoms of the same element have the same
a. atomic mass.
b. # of neutrons.
c. mass number.
____ 15. 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.
d. atomic number.
____ 16. An aluminum isotope consists of 13 protons, 13 electrons, and 14 neutrons. Its mass number is
a. 13.
b. 14.
c. 27.
d. 40.
____ 17. Carbon-14 (atomic number 6), the radioactive nuclide used in dating fossils, has
a. 6 neutrons.
b. 8 neutrons.
c. 10 neutrons.
d. 14 neutrons.
____ 18. Phosphorus-33 (atomic number 15) contains
a. 33 protons.
b. 18 neutrons.
c. 33 neutrons.
d. 18 protons.
Short Answer
19. What is the law of conservation of mass?
20. Describe the nucleus of an atom.
21. Give the location and relative charge of a proton.
22. What is the atomic number of an atom?
23. What is the mass number of an atom?
24. What is the relationship between isotopes, mass number, and neutrons?
Essay
25. Why do scientists use Dalton's theory, even though parts of it have been proven wrong? How much of
Dalton's theory do scientists still accept?
26. What can you determine about the atomic structure of an element if you know the atomic number of the
element and mass numbers of its isotopes? What additional information is needed to determine the average
atomic mass of the element? How do you determine the average atomic mass of the element?
Atomic Structure Practice Test
Answer Section
MULTIPLE CHOICE
1. ANS: C
Solution:
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18.
PTS:
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SC.B.1.4.2
B
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B
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B
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B
3
DIF: III
REF: 1
OBJ: 1
PTS: 1
DIF: I
REF: 1
PTS: 1
DIF: I
REF: 1
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DIF: I
REF: 2
DIF: I
REF: 2
DIF: I
REF: 2
DIF: II
REF: 2
DIF: I
REF: 2
DIF: I
REF: 2
DIF: I
REF: 2
DIF: II
REF: 3
DIF: I
REF: 3
DIF: I
REF: 3
DIF: I
REF: 3
DIF: I
REF: 3
DIF: III
REF: 3
DIF: III
REF: 3
DIF: III
REF: 3
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SC.A.2.4.1
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SC.A.2.4.1
SHORT ANSWER
19. ANS:
The statement that mass cannot be created or destroyed in ordinary chemical reactions.
PTS: 1
DIF: I
REF: 1
OBJ: 1
STA: SC.B.1.4.2
20. ANS:
An atom’s very small central region, which is made up of protons and neutrons.
PTS: 1
DIF: I
REF: 2
OBJ: 2
STA: SC.A.2.4.1
21. ANS:
A proton is a subatomic particle with a positive charge that is located in the nucleus of an atom.
PTS: 1
DIF: I
REF: 2
STA: SC.C.2.4.2
22. ANS:
The number of protons in the nucleus of an atom.
OBJ: 3
PTS: 1
DIF: I
REF: 3
STA: SC.A.2.4.3
23. ANS:
The sum of the number of protons and neutrons in an atom.
OBJ: 1
PTS: 1
DIF: I
REF: 3
OBJ: 1
STA: SC.A.2.4.3
24. ANS:
Isotopes are atoms of the same element with different numbers of neutrons, and therefore, different mass
numbers.
PTS: 1
STA: SC.A.2.4.3
DIF: II
REF: 3
OBJ: 2
ESSAY
25. ANS:
Dalton's theory led to the modern theory of the atom. Although scientists now know that atoms can be divided
and that elements exist as isotopes, most of his early theory is still accepted.
PTS: 1
DIF: II
REF: 1
OBJ: 3
STA: SC.B.1.4.2
26. ANS:
The atomic number equals the number of protons in the nucleus of an atom and also equals the number of
electrons in the neutral atom. The mass number is the sum of the number of protons and neutrons and can be
used, with the atomic number, to find the number of neutrons in each isotope. Each isotope of the element has
a different mass number but the same atomic number as the element.
In order to determine the average atomic mass of the element, you needed to know the relative
abundance and the exact mass of each isotope. Then, multiply the relative abundance (in decimal form) times
the atomic mass for each isotope, and adding the results.
PTS: 1
STA: SC.A.2.4.3
DIF: II
REF: 3
OBJ: 2