Elements and Compounds

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Elements and Compounds

Magnesium is made up of atoms only, so it is an element.

An element is a substance that is made up of one kind of atom only.

Every element has a name and a symbol and is displayed on the Periodic Table.

Element Symbol:
Carbon C
Hydrogen H
Aluminium Al
Sodium Na
Potassium K
Lithium Li
Silver Ag
Mercury Hg
Lead Pb

Elements can combine with each other to form compounds.

A compound contains two or more kinds of atoms joined together.

Elements and Compounds

The symbol for a compound is called its formula. It is made up from the symbols of the elements it contains and also tells us about the % composition of each element within the compound.

Example: H2O - A molecule of water contains 2 hydrogen atom for every oxygen atom.