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You are in:		Front Page > Science and Technology > Elementary

Home | About Atoms | The Periodic Table

	An element is a substance that can’t be divided chemically into anything more simple. It can be a metal or a non-metal, a solid, a liquid or a gas. But the point is, each element contains only one kind of atom.
	There are more than a hundred different elements in the universe.
	They could be arranged in alphabetical order but that wouldn't tell you much about their chemistry. Instead, they are arranged in The Periodic Table, according to their atomic number.

Salt is not an element.
Why?

Because it can be divided into two different elements - sodium and chlorine - which is why the scientific name for salt is sodium chloride.

Iron is an element.
Why?

Because it’s made up of iron atoms only.

Water is not an element.
Why?

Because it's made up of two different elements - hydrogen (H) and oxygen (O). Each molecule of water contains twice as much hydrogen as oxygen. So the formula for water is H20.

Oxygen is an element.
Why?

Because it contains only one kind of atom - oxygen. Oxygen atoms often exist in pairs (O2). These O2 molecules are found in the air.



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