Except for Group 18, most nonmetals readily form compounds with other elements. Many metals and nonmetals react with each other. Because atoms of nonmetals usually gain electrons, electrons move from metal atoms to nonmetal atoms. Nonmetals can also form compounds with other nonmetals by sharing electrons.
Non-metals are the elements in groups 14-16 of the periodic table. Non-metals are not able to conduct electricity or heat very well. As opposed to metals, non-metallic elements are very brittle, and cannot be rolled into wires or pounded into sheets.
The non-metals exist in two of the three states of matter at room temperature: gases (such as oxygen) and solids (such as carbon). The non-metals have no metallic luster, and do not reflect light. They have oxidation numbers of ±4, -3, and -2.
The Non-Metal elements are:
Hydrogen
Carbon
Nitrogen
Oxygen
Phosphorus
Sulfur
Selenium
Tip! Get step by step instructions to memorize the periodic table of the elements, including printable tables and a blank practice table at Chemistry.about.com.