What are Chemical Elements and Compounds?

Chemical Elements and Compounds Explained

An element is the simplest known substance, so cannot be broken down through a chemical reaction. A chemical reaction causes a substance to change into one or more different substances.

Elements formed in stars at the point when the universe was created. Iron, silver, gold, beryllium, hydrogen, carbon, nitrogen, and oxygen are some of the 118 known chemical elements. The full list is in the Periodic Table.

An element contains one type of atom. An atom is the smallest particle of a chemical element. When the same types of atoms come together, they create an element.

Oxygen is a chemical element because it only contains oxygen atoms. 

When more than one chemical element is present, it becomes known as a chemical compound. A compound is two or more chemical elements that have been combined.

An example of a chemical compound is water because it's made up of two hydrogen atoms and one oxygen atom.
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When two or more atoms bond together, they form a larger particle known as a molecule. It can take many thousands of atoms to form a single molecule.

Molecules can be different shapes and sizes. When many stack together in an orderly, repeating arrangement, they form a crystal lattice which extends in all directions.

The lattice is the highly ordered arrangement of atoms that forms a crystal.

Atoms are the basic building blocks of matter. They're minute particles that makeup everything around us.

Molecules are combinations of atoms that form more complex structures.

Most minerals are chemical compounds, which means they're made up of two or more chemical elements. Minerals made up of a single element are known as native elements. Examples of native elements include copper, carbon, gold, titanium, sulphur, chromium and vanadium.

An element can be a liquid, solid or gas. Bromine and mercury are the only liquids, while oxygen and hydrogen are gases.

Chemical compounds can also be liquid, solid or gas. Water is hydrogen and oxygen. Carbon dioxide is carbon and oxygen.  Solid chemical compounds are minerals. 

Quartz is a solid chemical compound made up of silicon and oxygen, specifically SiO₂, silicon dioxide. This means it's composed of one atom of silicon and two of oxygen.

Halite is another solid compound composed of one sodium atom and one chlorine atom. Sodium chloride is better known as salt. "Chlorine" becomes "chloride" when it bonds with another element, like sodium, to form a compound.

Article Photos

Pop-up photos: Gold, Halite - Courtesy of Stan Celestian. Sulphur - Courtesy of Géry Parent. 

The quartz crystal is from our collection.