Chapter 4: Section 4

 Are poor conductors, have reactivity, solid nonmetals are dull, brittle, non- malleable, non-ductile.

 Lower densities than metals

 Ten out of the 16 are gases at room temperature

Iodine, sulfur, and carbon are solids at room temperature Bromine is a liquid at room temperature

 Most are reactive and readily form into compounds

 Fluorine is the most reactive

 Usually gain or share electrons

 When they gain an electron(s) from a metal it forms an ionic bond

When the share electrons with other nonmetals it forms a covalent bond

 The carbon family: column 14

 Each element can gain, lose, or share 4 electrons (have 4 valance electrons)

 Only carbon is a nonmetal

Carbon is found in all living things Makes coal, gas, and oil (hydrocarbons)

 Nitrogen and phosphorus are the nonmetals

Gain or share 3 electrons ( have 5 valance electrons)

 Air is 80% Nitrogen  Nitrogen does not react readily  Diatomic molecules  Element that exists in nature as two atoms

Contains oxygen, sulfur, and selenium which are nonmetals

 Usually gain or share 2 electrons (have 6 valance electrons)

 Oxygen is diatomic and triatomic (ozone- layer in atmosphere which screens out harmful radiation from the sun, is dangerous at ground level due it being highly reactive)

Oxygen reacts readily and is the most abundant element in the earth’s crust, and 2nd most abundant in the atmosphere

The halogen family: Column 17  All but Astatine are nonmetals

 Gains or shares one electron (Have 7 valance electrons)

Called salt formers

 Very reactive and dangerous to humans

 Compounds that they form are very useful

 The Noble gases: Column 18

They usually do not form compounds because they usually do not gain, lose, or share electrons. They have 8 electrons in their valance shell-this is a stable configuration

 Exist in the earth’s atmosphere

 Top of column 1  Has only one proton and electron

Makes up 90% of the atoms in the universe Its chemical properties differ very much from those of the other elements, it cannot be grouped into a family

 Elements found in families 13-17, boundary between metals and non- metals on the table, forms a staircase

Have characteristics of both metals and nonmetals All are solids. Brittle, hard, good and somewhat reactive

 Most common is Silicon

 Most useful properties is their varying ability to conduct electricity-depends on temperature, exposure to light, and impurities. This is why they are called semiconductors