Group 16—The Oxygen Family The first two members of Group 16, oxygen and sulfur, are essential for life. The heavier mem- bers of the group, tellurium and polonium, are both metalloids.
About 20 percent of Earth’s atmosphere is the oxygen you breathe. Your body needs oxy- gen to release the energy from the foods you eat. Oxygen is abundant in Earth’s rocks and minerals because it readily combines with other elements. Oxygen also is required for combus- tion to occur. Foam is used in fire fighting to keep oxygen away from the burning item, as shown in Figure 10. Ozone, a less common form of oxygen, is formed in the upper atmo- sphere through the action of electricity during thunderstorms. The presence of ozone is important because it shields living organisms from some harmful radiation from the Sun.
Sulfur is a solid, yellow nonmetal. Large amounts of sulfur are used to manufacture sulfuric acid, one of the most commonly used chemicals in the world. Sulfuric acid is a combination of sulfur, hydrogen, and oxygen. It is used in the manufacture of paints, fertilizers, detergents, synthetic fibers, and rubber.
Selenium conducts electricity when exposed to light, so it is used in solar cells, light meters, and photographic materials. Its most important use is as the light-sensitive component in photo- copy machines. Traces of selenium are also necessary for good health.
Oxygen 8 O
Group 16 The Oxygen Family
Sulfur 16 S
Selenium 34 Se
Tellurium 52 Te
Polonium 84 Po
Poison Buildup Arsenic disrupts the normal func- tion of an organism by disrupting cellular metab- olism. Because arsenic builds up in hair, forensic scientists can test hair samples to confirm or dis- prove a case of arsenic poisoning. Tests of Napoleon’s hair suggest that he was poisoned with arsenic. Use refer- ence books to find out who Napoleon I was and why someone might have wanted to poison him.
Figure 10 The foam used in aircraft fires forms a film of water over the burning fuel which suffocates the fire.