1.
Which particle has the smallest mass?
A.
neutron
B.
proton
C.
electron
D.
helium nucleus
2.
An atom with 15 protons and 16 neutrons is an atom of
A.
P
B.
Ga
C.
S
D.
Pd
E.
Rh
3.
Atoms of the same element having the same atomic number but different mass numbers are called
A.
isomers
B.
orbitals
C.
neutrons
D.
isotopes
E.
nuclei
4.
The atom with 68 neutrons and 50 protons has a mass number of
A.
68
B.
50
C.
18
D.
118
E.
cannot be determined from information given
5.
The mass number of an atom equals
A.
the number of neutrons per atom
B.
the atomic mass of the element
C.
the atomic number of the element
D.
the number of protons plus the number of neutrons per atom
E.
none of the above
6.
How many neutrons are contained in an iodine nucleus with a mass number of 131?
A.
53
B.
74
C.
78
D.
127
E.
131
7.
The number of protons in the nucleus of an atom is called its
A.
mass number
B.
valence
C.
isotope number
D.
atomic number
E.
none of these
8.
Choose the pair in which the components have the same charge.
A.
a proton and a hydrogen atom
B.
a hydrogen atom and an electron
C.
a neutron and a hydrogen atom
D.
an electron and a neutron
9.
Which of the following is a nonmetal?
A.
cerium
B.
cesium
C.
carbon
D.
calcium
E.
copper
10.
An atom with 45 protons has a mass number of 100. It must contain how many neutrons?
A.
145
B.
45
C.
100
D.
55
E.
none of these
11.
How many electrons are present in a fluorine, F, atom?
A.
9
B.
10
C.
11
D.
18
E.
19
12.
How many protons are in the nucleus of a Mg atom?
A.
12
B.
24
C.
25
D.
36
E.
variable
13.
Which of the following elements is an alkali metal?
A.
Ca
B.
Cu
C.
Fe
D.
Na
E.
Sc
14.
Which of the following elements is an alkaline earth metal?
A.
Ca
B.
Cu
C.
Fe
D.
Na
E.
Sc
15.
Which of the following is a noble gas?
A.
Ar
B.
N
2
C.
H
2
D.
O
2
E.
CO
2
16.
Which of the following elements is most similar to chlorine?
A.
H
B.
He
C.
Na
D.
Hg
E.
Br
17.
Beta particles are
A.
electrons
B.
protons
C.
neutrons
D.
helium nuclei
E.
x-rays
18.
Choose the particle having a relative mass of 1 amu and no charge.
A.
alpha particle
B.
beta particle
C.
proton
D.
neutron
E.
none of these
19.
The atomic particle having a mass of 1 amu and a charge of 1+ is
A.
an electron
B.
a neutron
C.
an alpha particle
D.
a proton
E.
none of these
20.
The half-life of a radioactive nuclide is
A.
that period of time in which 25% of the original number of atoms undergoes radioactive decay.
B.
the time at which the isotope becomes nonradioactive
C.
that period of time in which 50% of the original number of atoms undergoes radioactive decay.
D.
the period of time it takes to reduce the radioactivity by 100%
E.
none of the above
21.
Strontium-90 from radioactive fallout is a health threat because, like ______________, it is incorporated into bone.
A.
iodine
B.
cesium
C.
iron
D.
calcium
E.
uranium
22.
The average mass of a boron atom is 10.81. Assuming you were able to isolate only one boron atom, the chance that you would randomly get one with a mass of 10.81 is
A.
0%
B.
0.81%
C.
about 11%
D.
10.81%
E.
greater than 50%
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