By Doug Johnson | Updated March 24, 2022
Metals are indispensable to human life and the planet’s infrastructure. They typically conduct heat and electricity, exhibit durability, and have high melting points. Nonmetals, while lacking some of these traits, share core atomic and chemical characteristics with metals.
Metals are strong, conductive, and high‑melting. Nonmetals differ in many ways, yet both are built from protons, neutrons, and electrons, can change state, and form compounds.
Metals dominate the Earth's crust—aluminum, iron, sodium, and potassium are prime examples. Potassium, for instance, is essential in human physiology. Nonmetals also play crucial roles: carbon, the backbone of life’s organic molecules, is abundant in the crust; hydrogen and oxygen combine to form water, covering most of the planet’s surface and sustaining life.
Both metals and nonmetals are elements that can form compounds, undergo phase changes, and participate in chemical reactions. While metals usually crystallize, nonmetals appear in a variety of states—from gases like noble gases to solids. Every element can transition between solid, liquid, and gas under appropriate temperature and pressure conditions, and each can engage in reactions that alter state or release energy.
About 75 % of the periodic table’s elements are metals, occupying the left side. Nonmetals reside on the right, with metalloids bridging the two. Metalloids such as boron, silicon, and germanium display limited conductivity at room temperature but become effective conductors when heated, and they are essential in semiconductor and ceramic technologies.
