Dmitri Mendeleev's version of the periodic table has been the most useful since he created it over 60 years ago. The table of elements are presented in groups of number of outer electrons (group) and the number of rings in an atom (period).
Group One Elements:
Lithium, Sodium, Potassium. (Alkali Metals)
- Very reactive in air and oxidise quickly.
- Have to be stored in oil…