There are 92 naturally occurring elements. The elements in any one column are said to be a family of elements. These are closely related element because they behave similarly in chemical reactions. Isotopes Atoms which have the same atomic number but different mass numbers. Chemical Symbol is an abbreviation for compounds and elements either a capital letter or a capital letter followed by a lower case letter.
Single symbols represent elements and combination symbols represent compounds.
The combination of symbols represents a particular compound. This indicates which elements are in a compound and in what proportion they represent. All matter is made up of tiny particles. The Atomic Theory states that All matter is made up of tiny particles called atoms Atoms of one element are the same. When other atoms combine with other atoms they create molecules.