Download Unit Review III

Chemistry Review Unit III (Atomic Structure)
__ 1)
Rutherford was able to show that the (volume, mass) _______________ of the nucleus is
large in relation to the atom.
__ 2)
Most of the volume of an atom is _______________.
__ 3)
The particles in the nucleus are called _______________.
__ 4)
The total number of protons in the nucleus of an atom is the _______________.
__ 5)
The total number of nucleons in the nucleus of an atom is the _______________.
__ 6)
Atoms with the same atomic number but different mass numbers are called __________.
__ 7)
Nucleons having a mass of about 1 amu and no charge are called _______________.
__ 8)
Neutral atoms have
a) more negative charge than positive charge
b) more positive charge than negative charge
c) variable amounts of charge
d) equal amounts of positive and negative charge
__ 9)
A particle that is present in every atom is the
a) positron
b) proton
c) neutron
d) neutrino
__ 10) The charge on the nucleus of an atom is due to
a) neutrons
b) positrons
c) protons
d) electrons
__ 11) All atoms of a given element have the same
a) number of nucleons
b) number of protons
c) number of neutrons
d) atomic mass
__ 12) The neutrons of an atom
a) revolve around the nucleus
b) contribute to the atomic weight
c) are positively charged
d) determine the atomic number
__ 13) The subatomic particles that have equal but opposite charges are
a) proton and electron
b) nucleon and neutron
c) neutron and proton
d) neutron and electron
__ 14) Which of the following particles has the smallest mass?
a) proton
b) neutron
c) alpha particle
d) electron
__ 15) A pure substance whose atoms have all the same atomic number is
a) a compound
b) an element
c) a radical
d) a mixture
__ 16) An atom containing 9 protons, 10 neutrons and 9 electrons has a mass number of
a) 28
b) 19
c) 18
d) 9
__ 17) The standard now used for atomic weight is
a) 16O
b) 1H
c) 32S
d) 12C
__ 18) The atomic mass of phosphorus is 30.97. This fractional mass is due to the existence of
two or more
a) compounds
b) isomers
c) isotopes
d) ions
__ 19) The electron has approximately 1/1836 of the mass of
a) an atom of plutonium
b) the nucleus of 1H
c) the nucleus of 2H
d) an atom of iron
__ 20) Compare the proton and the electron from the standpoint of each of the following:
a) mass
b) magnitude of charge
c) sign of charge
__ 21) Compare the proton and the neutron from the standpoint of each of the following:
a) mass
b) magnitude of charge
c) sign of charge
__ 22) Distinguish between the atomic number and the mass number. Distinguish between the
mass number and the atomic weight that appears in the Periodic Table.
__ 23) How many electrons are in a neutral atom of 7Li?
a) 7
b) 10
c) 3
d) 4
__ 24) The nucleus of a fluorine atom has a charge of
a) +1
b) +9
c) +19
d) 0
__ 25) The number of protons in the nucleus of 13C is
a) 19
b) 13
c) 7
d) 6
__ 26) The mass number of an atom is equal to the number of its
a) electrons, only
b) protons, only
c) electrons and protons
d) neutrons and protons
__ 27) The existence of fractional masses (e.g., 12C: m = 12.011 amu) is best explained by the
a) mass of electrons
b) existence of isotopes
c) inaccuracies in determining atomic masses
d) varying numbers of protons in an atom's nucleus
__ 28) Isotopes of an element have a different
a) number of electrons
b) number of protons
c) atomic number
d) number of neutrons
__ 29) Isotopes of an element have the same number of
a) protons and electrons
b) protons and neutrons
c) neutrons
d) nucleons
__ 30) Which pair of nuclei contain the same number of neutrons?
7 Li
9 Be
a)
and
3
4
40 K
40 Ar
b)
and
19
20
23
22 Na
c)
11 Na and
11
23
24 Mg
d)
11 Na and
12
__ 31) Which atom has an equal number of protons and neutrons?
1 H
a)
1
12 C
b)
6
19 F
c)
9
39
d)
19 K
__ 32) An atomic mass unit is equal to
a) the mass of a hydrogen molecule
b) 1/1836 the mass of a hydrogen atom
c) the mass of a 12C atom
d) 1/12 of the mass of a 12C atom
__ 33) The characteristic bright-line spectrum of an element is produced when electrons
a) fall back to lower energy levels
b) are gained by a neutral atom
c) are emitted by the nucleus as beta particles
d) move to higher energy levels
__ 34) How many electrons, neutrons and protons are in atoms of chlorine with the mass
number 35?
# of electrons =
# of neutrons =
# of protons =
__ 35) How many electrons, neutrons and protons are in atoms of thorium with the mass number
232?
# of electrons =
# of neutrons =
# of protons =
__ 36) Why are the lowest energy levels in an atom closest to the nucleus?
__ 37) Compute the average atomic mass of silver (Ag), if 51.83% of the silver atoms occurring
in nature have the mass 106.905 amu and 48.17% of the atoms have the mass of
108.905 amu.
__ 38) Compute the average atomic mass of krypton (Kr) if the relative amounts are as follows:
Isotope mass (in amu)
Abundance (in %)
77.920
0.350
79.916
2.27
81.913
11.56
82.914
11.55
83.912
56.90
85.911
17.37
__ 39) What are the two major groups of subatomic particles?
What are the differences between them?
__ 40) Briefly describe Rutherford's experiment and the subsequent revision of Thomson's
model of the atom.
__ 41) How does the energy of a wave change with its wavelength? How does it change with
frequency? How does the color of visible light relate to its energy/wavelength/frequency?
__ 42) What is the atomic mass of hafnium (Hf) if, out of every 100 atoms, 5 have mass 176, 19
have mass 177, 27 have mass 178, 14 have mass 179, and 35 have mass 180?
Answers
1)
mass
2)
empty space
3)
nucleons
4)
atomic number
5)
mass number
6)
isotopes
7)
neutrons
8)
D
9)
B
10)
C
11)
B
12)
B
13)
A
14)
D
15)
B
16)
17)
18)
19)
20)
21)
22)
23)
24)
25)
26)
B
D
C
B
a) p+ > eb) p+ = ec) + vs. a) p+ = no
b) p+ > no
c) + vs. neutral
(see notes)
C
B
D
D
27)
28)
29)
30)
31)
32)
33)
34)
35)
36)
37)
38)
39)
40)
41)
B
D
A
D
B
D
A
17, 18, 17
90, 142, 90
(see notes)
107.868 amu
83.801 amu
(see notes)
(see notes)
(see notes)
42)
178