Nonmetal
Nonmetals or non-metals are chemical elements which do not have the properties of a metal.
They gain electrons when reacting with a metal. They are generally not lustrous and are bad conductors of heat and electricity. Some are gases including: hydrogen, helium, oxygen, nitrogen, fluorine, neon or radon and others. An example of a solid that is a nonmetal is sulfur. It is yellow and not shiny at all. An example of a liquid that is a nonmetal is bromine. It is red. A non-metal is a good insulator for heat and cold. Usually, gases or brittle solids are non-metals.
Elements on the periodic table can be classified as metal, semimetal, or non-metal. Five times more elements are metals than nonmetals. However, nonmetals are abundant and important. Two of the nonmetals—hydrogen and helium—make up over 99 per cent of the observable Universe, and one—oxygen—makes up close to half of the Earth's crust, oceans and atmosphere. Living organisms are also composed almost entirely of nonmetals, and nonmetals form many more compounds than metals.
Nonmetal Media
While arsenic (here sealed in a container to prevent tarnishing) has a shiny appearance and is a reasonable conductor of heat and electricity, it is soft and brittle and its chemistry is predominately nonmetallic.
Red fuming nitric acid: A nitrogen-rich compound, incorporating nitrogen dioxide (NO2), an acidic oxide used in the production of nitric acid
Electronegativity values of the group 16 chalcogen elements showing a W-shaped alternation or secondary periodicity going down the group
Molecular structure of pentazenium, a homopolyatomic cation of nitrogen with the formula N+5 and structure N−N−N−N−N.
A small (about 2 cm long) piece of rapidly melting argon ice
Selenium conducts electricity around 1,000 times better when light falls on it, a property used in light-sensing applications.
The Alchemist Discovering Phosphorus (1771) by Joseph Wright. The alchemist is Hennig Brand; the glow emanates from the combustion of phosphorus inside the flask.
Greek philosopher Aristotle (384–322 BCE) categorized substances found in the earth as either metals or "fossiles".