Nonmetal

Nonmetals are special kinds of elements that are not metals. They have different properties from metals and are important in many things we see and use every day. Some nonmetals, like hydrogen and helium, are gases that are very light and can float. Others, like iodine, are shiny and solid. Nonmetals usually don't conduct heat or electricity very well, which makes them useful in many technologies.

There are seventeen elements that are widely known as nonmetals. These include gases like hydrogen and helium, and solids like carbon and sulfur. Together, hydrogen and helium make up about 98% of everything we can see in the universe. On Earth, nonmetals are very important because they are part of the air we breathe, the water we drink, and even the ground we walk on.

Nonmetals are used in many industries. For example, they are important in making electronics, helping engines burn fuel, and creating products that reduce friction. Scientists have been studying nonmetals for many years, and they continue to find new ways to use them in our everyday lives.

Definition and applicable elements

Unless otherwise noted, this article describes the stable form of an element at standard temperature and pressure (STP).

Nonmetallic chemical elements are elements that do not have the usual properties of metals, such as shininess, flexibility, or the ability to conduct heat and electricity well. Because of how their electrons are arranged band structure, they behave differently from metals.

Fourteen elements are almost always recognized as nonmetals:

• Hydrogen
• Nitrogen
• Oxygen
• Sulfur
• Fluorine
• Chlorine
• Bromine
• Iodine
• Helium
• Neon
• Argon
• Krypton
• Xenon
• Radon

Three more are often considered nonmetals, but some sources group them with elements called "metalloids":

• Carbon
• Phosphorus
• Selenium

Some elements usually called metalloids can also be counted as nonmetals by some scientists:

• Boron
• Silicon
• Germanium
• Arsenic
• Antimony
• Tellurium

Together, nonmetals make up about 15–20% of all known elements.

General properties

Nonmetals are elements that do not have typical metallic properties. They can be gases, like hydrogen, or solids, like carbon, and they often look different from metals. Some nonmetals are colorless, while others are colorful or even shiny.

Most nonmetals are gases or solids at normal temperatures. They are usually lighter and do not conduct heat or electricity well. Their shapes and forms can vary a lot, from soft and pliable to hard and brittle.

Types

Different ways to group nonmetals exist, with some grouping them into just two types and others into up to seven. For example, one common way to group them includes noble gases, halogens, and other nonmetals. Another way looks at seven color groups on a special chart that include nonmetals.

There are three main types of nonmetals starting on the right side of the periodic table:

• The noble gases — helium, neon, argon, krypton, xenon, and radon. These are not very reactive.
• The halogen nonmetals — fluorine, chlorine, bromine, and iodine. These are very reactive.
• The "unclassified nonmetals" — hydrogen, carbon, nitrogen, oxygen, phosphorus, sulfur, and selenium. These have mixed reactivity and don’t have a common name.

Some people also consider metalloids, such as boron and silicon, as a fourth group. These elements have properties of both metals and nonmetals, making their classification tricky.

Noble gases

Main article: Noble gas

Six nonmetals are noble gases: helium, neon, argon, krypton, xenon, and radon. They are found in the far right column of the periodic table and are called noble gases because they hardly react with other elements. They are colorless, smellless, and do not catch fire. Because their outer electron shells are full, noble gases melt and boil at very low temperatures.

Halogen nonmetals

Main article: Halogen

The halogen nonmetals — fluorine, chlorine, bromine, and iodine — are very reactive. They easily lose or gain electrons and have strong pulling power on other elements. They usually form compounds with metals, unlike most other nonmetals.

Unclassified nonmetals

Hydrogen acts sometimes like a metal and sometimes like a nonmetal. For example, it can form bonds like a metal in water or like a nonmetal in hydrochloric acid. These nonmetals are less reactive than halogens and can be found in nature. They can form special compounds with metals and often bond to themselves, especially in solid forms.

Abundance, extraction, and uses

The elements in the universe come from processes in stars and radioactive changes. Some nonmetal elements, like the noble gases, are less common in Earth's air than we might expect. Scientists study these differences to learn more about our planet.

Several important nonmetals make up most of Earth’s surface, air, water, and living things. These include hydrogen, carbon, nitrogen, oxygen, and silicon. They help form the rocks of Earth’s crust and are key for life.

We get many nonmetals from natural gas, air, seawater, and mining. For example, nitrogen and oxygen are taken from air, and chlorine comes from seawater. Nonmetals have many uses: hydrogen can help power clean energy, carbon is in diamonds and graphite, oxygen helps us breathe and powers fires, and silicon is used in many electronic devices. Noble gases like helium and argon have special uses, such as keeping things very cold or stopping fires safely.

Taxonomical history

Medieval thinkers mainly studied metals and rarely looked into nonmetallic minerals.

French chemist Antoine Lavoisier made big changes in chemistry. In 1789, he created the first modern list of chemical elements. He grouped the 33 known elements into four types: gases, metals, nonmetals, and earths. His work was very important and was published in many languages.

Later scientists added new ways to sort elements. In 1802, the word "metalloids" was used for elements that had some properties of metals and some of nonmetals. By the mid-1800s, scientists like Alphonse Dupasquier organized nonmetals into groups such as organogens (oxygen, nitrogen, hydrogen, carbon) and chloroides (fluorine, chlorine, bromine, iodine). These early groupings helped shape how we understand elements today.

Comparison of selected properties

See also § Physical

Physical properties are shown in a simple list, making it easy to see how different elements behave.

See also § Chemical

Chemical properties are shown from general traits to more detailed points.

† Hydrogen can also form special mixtures with metals
‡ The words low, moderate, high, and very high are used to describe values in the table.