Chapter 20:
Elements and Their Properties
Practice Test
1.
On a circle graph showing the percentage of elements in the human body, the wedge representing nitrogen takes up 10.8°. What is the percentage of nitrogen in the human body?
a.
33.3%
b.
0.83%
c.
10.8%
d.
3%
Hint
2.
The synthetic element hassium-261 has a half-life of 9.3 s. The synthetic element fermium-255 has a half-life of 20.1 h. How many times longer is the half-life of fermium-255 than the half-life of hassium-261?
a.
7,780
b.
0.46
c.
2.16
d.
130
Hint
3.
A metal bolt with a mass of 26.6 g is placed in a 50 ml graduated cylinder containing water. The water level in the cylinder rises from 27.0 ml to 30.5 ml. What is the density of the bolt in g/cm
3
?
a.
7.6 g/cm
3
b.
0.13 g/cm
3
c.
0.87 g/cm
3
d.
1.2 g/cm
3
Hint
4.
There are three isotopes of hydrogen. The isotope deuterium, with one proton and one neutron in the nucleus, makes up 0.015% of all hydrogen atoms. Of every million hydrogen atoms, how many are deuterium?
a.
1,500
b.
150
c.
15
d.
15,000
Hint
5.
The melting point of aluminum is 660.0 °C. What is the melting point of aluminum on the Fahrenheit temperature scale?
a.
1,188 °F
b.
334.7 °F
c.
330 °F
d.
1,220 °F
Hint
6.
In seawater the concentration of fluoride ions, F
-
, is 1.3 × 10
-3
g/L. How many liters of seawater would contain 1.0 g of F
-
?
a.
100 L
b.
770 L
c.
7,700 L
d.
130 L
Hint
7.
A certain gold ore produces about 5 g of gold for every 1,000 kg of ore that is mined. If one ounce = 28.3 g, how many kg of ore must be mined to produce an ounce of gold?
a.
5,660 kg
b.
176 kg
c.
141 kg
d.
28,300 kg
Hint
8.
The density of silver is 10.5 g/cm
3
and the density of copper is 8.9 g/cm
3
. What is the difference in mass between a piece of silver with a volume of 5 cm
3
and a piece of copper with a volume of 5 cm
3
?
a.
8.0 g
b.
16.0 g
c.
80.0 g
d.
1.6 g
Hint
9.
A vitamin and mineral supplement pill contains 1.0 × 10
-5
g of selenium. According to the label on the bottle, this amount is 18% of the recommended daily value. What is the recommended daily value of selenium in g?
a.
1.8 × 10
-4
g
b.
5.5 × 10
-5
g
c.
5.5 g
d.
1.8 × 10
-5
g
Hint
10.
A person has a mass of 68.3 kg. If 65% of the mass of a human body is oxygen, what is the mass of oxygen in this person's body?
a.
1.05 kg
b.
65 kg
c.
0.95 kg
d.
44.4 kg
Hint
