Key K Review Unit 6
Fill in the following chart.
Isotope
1.
Oxygen-16
2.
Selenium-80
3.
Uranium-235
4.
Chlorine-36
Isotope
Notation
𝟏𝟔
𝑶
𝟖
80
Se
34
𝟐𝟑𝟓
𝑼
𝟗𝟐
36 −1
Cl
17
Atomic #
Protons
Electrons
Neutrons
8
8
8
8
34
34
34
46
92
92
92
143
17
17
18
19
5. This experimental set-up was used by which
scientist?
A)
Bohr
C)
Chadwick
B)
Dalton
D)
Rutherford
6. Identify the charges of the protons, neutrons, and electrons.
A) protons +1, neutrons 0, electrons -1
B) protons 0, neutrons -1, electrons +1
C) protons -1, neutrons 0, electrons +1
D) protons 0, neutrons +1, electrons -1
E) protons +1, neutrons -1, electrons 0
7. The mass number is equal to
A) the sum of the number of the electrons and protons.
B) the sum of the number of the neutrons and electrons.
C) the sum of the number of protons, neutrons, and electrons.
D) the sum of the number of protons and neutrons.
8. What does "X" represent in the following symbol?
X
A) mercury
B) chlorine
C) scandium
D) bromine
E) selenium
9. Determine the number of protons, neutrons and electrons in the following:
X
A) p+ = 18
B) p+ = 18
C) p+ = 22
D) p+ = 18
n° = 18
n° = 22
n° = 18
n° = 22
e- = 22
e- = 18
e- = 18
e- = 40
E) p+ = 40
n° = 22
e- = 18
10. Which of the following statements about subatomic particles is TRUE?
A) A neutral atom contains the same number of protons and electrons.
B) Protons have about the same mass as electrons.
C) Electrons make up most of the mass of an atom.
D) Protons and neutrons have opposite, but equal in magnitude, charges.
E) Neutrons and electrons are found in the nucleus of an atom.
11. Write the isotope notation for an atom using the information below.
p+ = 47
n° = 62 e- = 46 𝟏𝟎𝟗𝑨𝒈+𝟏
𝟒𝟕
12. Calculate the atomic mass of silver if silver has 2 naturally occurring isotopes with the following masses
and natural abundances:
Isotope
Percent abundance
Ag-107
51.84%
Ag-109
48.46%
A) 107.90 amu
(.5184 * 107) + (.4846 * 109) = 108.29 amu
B) 108.00 amu
C) 107.79 amu
D) 108.29 amu
13. How many xenon atoms are contained in 2.36 moles of xenon?
A) 3.92 × 1024 xenon atoms 2.36 moles X (6.02 X 1023atoms/1 mole) = 1.42 × 1024 xenon atoms
B) 2.55 × 1023 xenon atoms
C) 1.42 × 1024 xenon atoms
D) 7.91 × 1025 xenon atoms
E) 1.87 × 1026 xenon atoms
14. An ion has 8 protons, 9 neutrons, and 10 electrons. The symbol for the ion is ________.
𝟏𝟕 -2
A
𝑶
𝟖
17
B) 𝑂+2
8
19 +1
C) 𝐹
9
19 -1
D) 𝐹
9
15. Which of the following statements about isotopes is TRUE?
A) Isotopes of the same element differ only in the number of electrons they contain.
B) An isotope of an atom with a larger number of neutrons is larger than an isotope of the same atom that
contains fewer neutrons.
C) Isotopes of the same element have the same mass.
D) Isotopes of the same element don't usually have the same properties.
E) Some elements have 3 or more naturally occurring isotopes.
16. The radioactive decay of carbon-14 to nitrogen-14 occurs by the process of
𝟏𝟒
𝟏𝟒
𝟎
A) Alpha decay
𝑪  𝑵 +
𝒆
𝟔
𝟕
−𝟏
B) Beta decay
C) Gamma decay
D) Fusion
17. Which of the following represents a pair of isotopes?
Atomic
Mass
Number
Number
14
(A) I.
6
II.
7
14
(B) I.
6
7
II.
14
14
(C) I.
6
14
II.
14
28
(D) I.
7
13
II.
7
14
(E) I.
8
10
II.
16
20
Use the following table to answer questions 18-23.
Atom
A
B
C
D
E
F
G
# of protons
9
9
9
10
10
11
11
# of neutrons
9
10
11
10
11
11
12
18. How many electrons would atom D need to be neutral? _____10________
19. What is the mass number for atom B? ______19_____
20. What element is represented by atom G? ____Na_______
21. How many different elements are shown in this table? _____3______
22. How many electrons would be needed for atom E to become an anion with a charge of -3 ? _____13_____
23. How many electrons would be needed for atom A to have a net charge of + 3 ? _____6______
24. Complete the following reaction and tell what kind of decay is occurring:
232
4
𝟐𝟐𝟖
𝑹𝒂 _______
𝟖𝟖
90 Th  2 He + ____
Type of Decay _alpha_________________
25. Describe a beta particle. _________a particle with negligible mass and a negative charge.
𝟎
𝒆
−𝟏
26. Define daughter nuclide. _The product of a nuclear decay. The parent nuclide minus the decay particle.
27. The most mass is lost by an atom during ____________alpha_____________ decay. Why? ___It has the mass of a
Helium atom.
28. Rank nuclear decay from most penetrating to least penetrating. Gamma, Beta, Alpha.
29. Which of the following statements is NOT correct in Dalton’s atomic model?
A) each element has its own type of atom
B) all matter is made of tiny particles called atoms
C) atoms of the same element are identical
D) atoms can be broken down into sub-atomic particles
30. Which atomic model was the first one to include electrons?
A) Dalton’s model
B) Rutherford’s electron cloud model
C) Thomson’s plum pudding model
D) Bohr’s planetary model
31. The cathode ray tube was instrumental in the discovery of:
A) the electron
B) the neutron
C) the proton
D) the atom, which is mostly empty space
32. Which atomic model was the first one to include a nucleus?
A) Dalton’s model
B) Rutherford’s model
C) Thomson’s plum pudding model
D) Bohr’s planetary model
33. What is the key difference between the models of the atom proposed by Bohr and Rutherford?
A) Bohr’s model includes a nucleus, but Rutherford’s does not
B) Bohr’s model has the atom made up of mostly empty space, but Rutherford’s does not
C) Bohr’s model includes neutrons, but Rutherford’s does not
D) Bohr’s model has the electrons moving in fixed energy levels, while in Rutherford’s they do not.
34. The gold foil experiment contributed to the discovery that:
A) atoms contain electrons
B) atoms are mostly empty space
C atoms contain a nucleus
D) both “b” and “c”
Match the following pictures to the Model. Label each model
with the name associated with the model
35
.
Modern Atom
38
_4_ Electrons travel not in orbits, but
exist as clouds of electric charge within
orbitals. 38
__2_ Atoms are indivisible, only
differing in size, shape and
arrangement. 36
Bohr
_3_ negatively charged electrons within
a sphere of positive electricity. 37
36
.
Democritus
_1__a dense, positively charged nucleus
surrounded by electrons traveling a
specific allowed orbits. 35
39.
.
_5__ a dense positively charged nucleus
and mostly empty space with an
occasional negative particle. 39
37
.
JJ Thomson
Rutherford