NAME
CHAPTER
4
REVIEW WORKSHEET
CALCULATE THE AVERAGE ATOMIC MASS FOR EACH ELEMENT BELOW. THEN IDENTIFY THE ELEMENT’S ATOMIC NUMBER,
# OF PROTONS,
# OF ELECTRONS AND # OF NEUTRONS. IN ORDER TO RECEIVE CREDIT, ALL CALCULATIONS MUST BE SHOWN. DON’T FORGET TO MAINTAIN SIGFIGS IN YOUR
CALCULATIONS. CIRCLE OR HIGHLIGHT ALL ANSWERS.
ISOTOPE
MASS (AMU)
84Sr
83.913425
85.9092624
86.9088793
87.9056143
86Sr
87Sr
88Sr
Average Atomic Mass
Atomic Number 38
# Protons
38
87.62
# Electrons
# Neutrons
ISOTOPE
38
50
MASS (AMU)
74Se
73.9224766
75.9192141
76.9199146
77.9173095
79.9165218
81.9167000
76Se
77
Se
78Se
80Se
82Se
Average Atomic Mass
Atomic Number 34
# Protons
34
% ABUNDANCE
0.46942
8.47065
6.08362
72.59246
87.6166
0.56
9.86
7.00
82.58
% ABUNDANCE
0.65791
7.11363
5.86894
18.52094
39.67635
7.15733
78.989
0.89
9.37
7.63
23.77
49.61
8.73
78.99
# Electrons
# Neutrons
34
45
NUMERIC RESPONSE:
ANSWER
3. How many protons are present in an atom of beryllium-10?
4
4. Determine the number of electrons in an atom of iridium?
77
5. What is the mass number for an oxygen atom that has 10 neutrons in its nucleus?
18
6. How many neutrons are in an atom of 235U?
143
7. What is the total number of subatomic particles in the nucleus of an atom of lead-209?
209
8. How many elements are presently recognized as of today?
118
9. COMPLETE
THE FOLLOWING TABLE.
ELEMENT
NAME
Nobelium
Rutherfordium
Yttrium
ATOMIC
NUMBER
102
# OF
# OF
# OF
No
MASS
NUMBER
259
PROTONS
102
ELECTRONS
102
NEUTRONS
159
METAL
NONMETAL
METALLOID
Metal
Rf
267
104
104
104
163
Metal
Y
89
39
39
39
50
Metal
SYMBOL
a.
b.
10.
atom
electron
The smallest particle of an element that retains the properties of that element is a(n) ____.
c. proton
d. neutron
11.
a.
b.
c.
d.
Which of the following is true about subatomic particles?
Electrons are negatively charged and are the heaviest subatomic particle.
Protons are positively charged and the lightest subatomic particle.
Neutrons have no charge and are the lightest subatomic particle.
The mass of a neutron nearly equals the mass of a proton.
12.
a.
b.
c.
d.
a.
b.
c.
d.
a.
b.
a.
b.
a.
b.
a.
b.
a.
b.
c.
d.
a.
b.
c.
d.
a.
b.
c.
d.
a.
b.
a.
b.
c.
d.
a.
b.
c.
d.
a.
b.
c.
d.
All atoms are ____.
positively charged, with the number of protons exceeding the number of electrons
negatively charged, with the number of electrons exceeding the number of protons
neutral, with the number of protons equaling the number of electrons
neutral, with the number of protons equaling the number of electrons, which is equal to the
number of neutrons
13.
The nucleus of an atom is ____.
the central core and is composed of protons and neutrons
positively charged and has more protons than neutrons
negatively charged and has a high density
negatively charged and has a low density
14.
The atomic number of an element is the total number of which particles in the nucleus?
neutrons
c. electrons
protons
d. protons and electrons
15.
The sum of the protons and neutrons in an atom equals the ____.
atomic number
c. atomic mass
nucleus number
d. mass number
16.
All atoms of the same element have the same ____.
number of neutrons
c. mass numbers
number of protons
d. mass
17.
Isotopes of the same element have different ____.
numbers of neutrons
c. numbers of electrons
numbers of protons
d. atomic numbers
18.
Which of the following statements is NOT true?
Atoms of the same element can have different masses.
Atoms of isotopes of an element have different numbers of protons.
The nucleus of an atom has a positive charge.
Atoms are mostly empty space.
19.
How is the number of neutrons in the nucleus of an atom calculated?
Add the number of electrons and protons together.
Subtract the number of electrons from the number of protons.
Subtract the number of protons from the mass number.
Add the mass number to the number of electrons.
20.
How do the isotopes hydrogen-1 and hydrogen-2 differ?
Hydrogen-2 has one more electron than hydrogen-1.
Hydrogen-2 has one neutron; hydrogen-1 has none.
Hydrogen-2 has two protons; hydrogen-1 has one.
Hydrogen-2 has one proton; hydrogen-1 has none.
21.
What unit is used to measure weighted average atomic mass?
amu
c. angstrom
gram
d. nanogram
22.
Which of the following equals one atomic mass unit?
the mass of one electron
the mass of one helium-4 atom
the mass of one carbon-12 atom
one-twelfth the mass of one carbon-12 atom
23.
Which of the following statements is NOT true?
Protons have a positive charge.
Electrons are negatively charged and have a mass of 1 amu.
The nucleus of an atom is positively charged.
Neutrons are located in the nucleus of an atom.
24.
The atomic mass of an element is the ____.
total number of subatomic particles in its nucleus
weighted average of the masses of the isotopes of the element
total mass of the isotopes of the element
average of the mass number and the atomic number for the element