Elements

Group 18 are all noble gases, they don't mix with other elements to become ions as they already have full shells of electrons and can not lose or gain electrons easily. Each of the elements only relate to one type of atom, compunds are a mix of more than one type of atom. Each element has a unique chemical symbol which can be viewed on the periodic table. On the periodic table the columns are called groups, and the horizontal line are called periods. You can figure out how many electrons are in the last shell by looking at the group number (group number = number of electrons in the last shell) but if the group number is for example: 16. then you take 6 as the number of electrons in its outer shell. What period the element is in determines how many electron shells the atom contains. For example: Na is in period 4, so it has 4 electron shells. Also Na is in group 1 meaning that in the outer electron shell there is only 1 electron. The electron(s) in the outer shell is reffered to as the valence electron(s).

First 20 elements

 * 1) Hydrogen **H**
 * 2) Helium **He**
 * 3) Lithium **Li**
 * 4) Beryllium **Be**
 * 5) Boron **B**
 * 6) Carbon **C**
 * 7) Nitrogen **N**
 * 8) Oxygen **O**
 * 9) Fluorine **F**
 * 10) Neon **Ne**
 * 11) Sodium **Na**
 * 12) Magnesium **Mg**
 * 13) Aluminium **Al**
 * 14) Silicon **Si**
 * 15) Phosphorus **P**
 * 16) Sulfur **S**
 * 17) Chlorine **Cl**
 * 18) Argon **Ar**
 * 19) Potassium **K**
 * 20) Calcium **Ca**

=**This is an easy way to remember the perodic table of elements! **= media type="youtube" key="SmwlzwGMMwc&hl=en&fs=1" height="344" width="425"