periodic+table+of+elements

=periodic table of elements=



= The periodic table of elements is a table that contains all the elements we know of. In 1689 Dmitri mendeleev made an element index cards. He orderd the cards from lightest to heaviest. This lead to a discovery-the properties of the elements repeat in cycles! He called it the periodic table of elements because the properties repeat in cycles(periods).There are 114 elements, 1 to 92 are stable, and 92 and up are unstable. Everything in the universe is made of elemants. = = = = Back to Science page =