Download chem pre ap atom and nuclear practice test

Topics Covered on the unit 2 Test:
Modern atomic theory – this includes the 4 scientists we studied, their experiments, and the
conclusions of these experiments
Isotopes/Atoms
Average atomic mass
Mole conversions
Nuclear chemistry
Unit 2 practice test
Multiple Choice
Identify the choice that best completes the statement or answers the question.
____
____
____
____
____
____
____
____
____
1. 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.
2. Which of the following statements is true?
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. Matter is composed of large particles called atoms.
3. The rays produced in a cathode tube in early experiments were
a. unaffected by a magnetic field.
c. found to carry a positive charge.
b. deflected away from a negative plate.
d. striking the cathode.
4. The discovery of the electron resulted from experiments using
a. gold foil.
c. neutrons.
b. cathode rays.
d. alpha particles.
5. Who discovered the nucleus by bombarding gold foil with positively charged particles and noting that some
particles were widely deflected?
a. Rutherford
c. Chadwick
b. Dalton
d. Bohr
6. Rutherford's experiments led to the discovery of the
a. electron.
c. nucleus.
b. cathode ray.
d. neutron.
7. The mass of a neutron is
a. about the same as that of a proton.
c. double that of a proton.
b. about the same as that of an electron.
d. double that of an electron.
8. The charge on the electron cloud
a. prevents compounds from forming.
b. balances the charge on the nucleus.
c. attracts electron clouds in other atoms to form compounds.
d. does not exist.
9. Isotopes are atoms of the same element that have different
a. principal chemical properties.
c. numbers of protons.
b. masses.
d. numbers of electrons.
____ 10. The atomic number of oxygen, 8, indicates that there are eight
a. protons in the nucleus of an oxygen atom.
b. oxygen nuclides.
c. neutrons outside the oxygen atom's nucleus.
d. energy levels in the oxygen atom's nucleus.
____ 11. The average atomic mass of an element is the average of the atomic masses of its
a. naturally occurring isotopes.
c. nonradioactive isotopes.
b. two most abundant isotopes.
d. artificial isotopes.
____ 12. The average atomic mass of an element
a. is the mass of the most abundant isotope.
b. may not equal the mass of any of its isotopes.
c. cannot be calculated.
d. always adds up to 100.
____ 13. Zn-66 (atomic number 30) has
a. 30 neutrons.
c. 36 neutrons.
b. 33 neutrons.
d. 96 neutrons.
____ 14. Phosphorus-33 (atomic number 15) contains
a. 33 protons.
c. 33 neutrons.
b. 18 neutrons.
d. 18 protons.
____ 15. The number of atoms in 1 mol of carbon is
a. 6.022  1022.
c. 5.022  1022.
b. 6.022  1023.
d. 5.022  1023.
____ 16. Molar mass
a. is the mass in grams of one mole of a substance.
b. is numerically equal to the average atomic mass of the element.
c. both a and b
d. neither a nor b
____ 17. The mass of two moles of oxygen atoms (atomic mass 16 amu) is
a. 16 g.
c. 48 g.
b. 32 g.
d. 64 g.
____ 18. A prospector finds 39.39 g of gold (atomic mass 196.9665 amu). She has
a. 1.20  1023 atoms.
c. 4.30  1023 atoms.
b. 2.30  1023 atoms.
d. 6.02  1023 atoms.
____ 21. Bohr's theory helped explain why
a. electrons have negative charge.
b. most of the mass of the atom is in the nucleus.
c. excited hydrogen gas gives off certain colors of light.
d. atoms combine to form molecules.
Short Answer
22. How has Dalton's theory about atomic particles been modified by modern science?
23. What is the relationship between isotopes, mass number, and neutrons?
24. Why do chemists work with moles instead of individual atoms?
Problem
25. How many atoms are present in 80.0 mol of zirconium?
26. How many moles of platinum are equivalent to 1.20  1024 atoms?
27. How many moles of iron are equivalent to 1.11  1025 atoms?
28. Determine the mass in grams of 5.00 mol of oxygen. The molar mass of oxygen is 16.00 g/mol.
29. Determine the mass in grams of 10.0 mol of bromine. The molar mass of bromine is 79.90 g/mol.
30. Calculate the number of atoms in 10.0 g of sulfur (molar mass 32.07 g/mol).
Essay
31. 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?
32. What can you determine about the atomic structure of an element and one of its isotopes if you know the
atomic number and mass numbers?
33. Explain the significance of Avogadro's constant, 6.022  1023. What is the relationship between it and the
molar mass of oxygen, 16.00 g/mol?
Unit 2 practice test
Answer Section
MULTIPLE CHOICE
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21.
ANS:
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C
A
B
B
A
C
A
B
B
A
A
B
C
B
B
C
B
A
D
D
C
PTS:
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1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
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1
SHORT ANSWER
22. ANS:
The discovery of subatomic particles proved that atoms are divisible. Dalton believed that atoms were
indivisible.
PTS: 1
23. ANS:
Isotopes are atoms of the same element with different numbers of neutrons and therefore different mass
numbers.
PTS: 1
24. ANS:
A mole is a collection of atoms that is large enough to measure in the laboratory. A single atom is too small.
PTS: 1
PROBLEM
25. ANS:
4.82  1025 atoms Zr
PTS: 1
26. ANS:
1.99 mol Pt
PTS: 1
27. ANS:
18.4 mol Fe
PTS: 1
28. ANS:
80.0 g O
PTS: 1
29. ANS:
799 g Br
PTS: 1
30. ANS:
1.88  1023 atoms S
PTS: 1
ESSAY
31. ANS:
Dalton's theory led to the modern theory of the atom. Although scientists now know that atoms can be
divided, most of his early theory is still accepted.
PTS: 1
32. 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. An isotope of an element has a different mass
number but the same atomic number as the element.
PTS: 1
33. ANS:
Avogadro's constant is the number of particles in 1 mol of a substance. Because the molar mass of oxygen
atoms is 16.00 g/mol, the mass of 1 mol, or 6.022  1023, oxygen atoms is 16.00 g.
PTS: 1
nuclear practice
Multiple Choice
Identify the choice that best completes the statement or answers the question.
____
1. What does the 4 in
represent?
a. the mass number
b. the atomic number
c. the number of protons
d. the number of neutrons
____
2. What does the 218 in polonium-218 represent?
a. the mass number
c. the mass defect
b. the atomic number
d. the neutron number
____
3. Between protons in a nucleus,
a. attraction due to nuclear force is greater than repulsion due to electrostatic force.
b. repulsion due to electrostatic force is greater than attraction due to nuclear force.
c. nuclear and electrostatic forces are balanced.
d. electrostatic forces are negligible.
____
4. Reactions that affect the nucleus of an atom are called
a. fusions.
c. radioactive decays.
b. fissions.
d. nuclear reactions.
____
5. Balance the following equation:
a.
+ ____
c.
b.
____
6. Balance the following equation:
d.
+ ____
+
a.
c.
b.
d.
____
7. The process that changes the identity and number of protons in a nucleus is
a. fusion.
c. fission.
b. transmutation.
d. All of the above
____
8. Which of the following is the symbol for an alpha particle?
a.
c.
b.
____
d.
9. Which of the following is the nuclear symbol for a beta particle?
a.
c.
b.
d.
____ 10. Which of the following is a fission reaction?
a. hydrogen-2 and hydrogen-3 combining to form a helium-4 atom and a neutron
b. carbon-12 and hydrogen-1 combining to form a nitrogen-13 atom
c. uranium-235 absorbing a neutron and breaking into barium-141, krypton-92, and three
neutrons
d. a glucose molecule being metabolized with oxygen to form carbon dioxide and water
____ 11. Scientists are investigating the possibility of containing fusion reactions within
a. steel containers.
c. concrete casks.
b. lead containers.
d. magnetic fields.
Short Answer
1. Briefly describe alpha particles, beta particles, and gamma rays.
Completion
Complete each statement.
1. The nuclide
2. The nuclide
contains ____________________ protons.
contains ____________________ neutrons.
3. The combination of the nuclei of small atoms to form a larger nucleus is called nuclear
____________________.
4. The splitting of the nucleus of a large atom into two or more fragments is called nuclear
____________________.
Problem
1. Write the nuclear equation for each of the following reactions. Refer to a periodic table.
a. the alpha decay of
b. the beta decay of
c. the positron emission of
Essay
1. Compare fusion, fission, and transmutation.
nuclear practice
Answer Section
MULTIPLE CHOICE
1. ANS:
REF:
2. ANS:
REF:
3. ANS:
REF:
4. ANS:
REF:
5. ANS:
REF:
6. ANS:
REF:
7. ANS:
REF:
8. ANS:
REF:
9. ANS:
REF:
10. ANS:
REF:
11. ANS:
REF:
A
PTS: 1
DIF:
d561954a-f97e-11de-9c72-001185f0d2ea
A
PTS: 1
DIF:
d5641eb7-f97e-11de-9c72-001185f0d2ea
A
PTS: 1
DIF:
d574a832-f97e-11de-9c72-001185f0d2ea
D
PTS: 1
DIF:
d5770a8f-f97e-11de-9c72-001185f0d2ea
B
PTS: 1
DIF:
d57e31a6-f97e-11de-9c72-001185f0d2ea
C
PTS: 1
DIF:
d5809403-f97e-11de-9c72-001185f0d2ea
D
PTS: 1
DIF:
d5831d70-f97e-11de-9c72-001185f0d2ea
D
PTS: 1
DIF:
d5986ba5-f97e-11de-9c72-001185f0d2ea
C
PTS: 1
DIF:
d59892b5-f97e-11de-9c72-001185f0d2ea
C
PTS: 1
DIF:
d5d8cb74-f97e-11de-9c72-001185f0d2ea
D
PTS: 1
DIF:
d5e4de55-f97e-11de-9c72-001185f0d2ea
SHORT ANSWER
1. ANS:
I
OBJ: 1
I
OBJ: 1
I
OBJ: 3
I
OBJ: 4
II
OBJ: 4
II
OBJ: 4
I
OBJ: 4
I
OBJ: 2
I
OBJ: 2
I
OBJ: 1
I
OBJ: 3
Alpha particles are helium nuclei that are emitted from heavy elements. Beta particles are high-energy
electrons emitted from nuclei when neutrons become protons. Gamma rays are high-energy electromagnetic
waves.
PTS: 1
OBJ: 2
DIF: II
REF: d5e740b2-f97e-11de-9c72-001185f0d2ea
PTS: 1
OBJ: 1
2. ANS: 118
DIF: I
REF: d5ee40b9-f97e-11de-9c72-001185f0d2ea
PTS: 1
OBJ: 1
3. ANS: fusion
DIF: II
REF: d5f0a316-f97e-11de-9c72-001185f0d2ea
PTS: 1
OBJ: 2
4. ANS: fission
DIF: I
REF: d5f30573-f97e-11de-9c72-001185f0d2ea
PTS: 1
OBJ: 2
DIF: I
REF: d5f58ee0-f97e-11de-9c72-001185f0d2ea
DIF: II
REF: d5fa2c8a-f97e-11de-9c72-001185f0d2ea
COMPLETION
1. ANS: 53
PROBLEM
1. ANS:
a.
b.
c.
PTS: 1
OBJ: 4
ESSAY
1. ANS:
In a transmutation, the identity of a nucleus changes because its number of protons changes. Fission and
fusion are two processes that change the number of protons. In fission, a heavy nucleus breaks up, decreasing
the number of protons. In fusion, light nuclei join, increasing the number of protons.
PTS: 1
OBJ: 1
DIF: II
REF: d5fef144-f97e-11de-9c72-001185f0d2ea