The Periodic Table

All About The periodic Table

The periodic table was organized in 1869 by a Russian chemist names Dmitri Mendeleyv. He put the elements in order by the elements weight. The rows that go horizontally are called periods, and the columns that go vertically are called families or groups. The representative elements are groups 1 and 13-18. The transition elements are groups 3-12 and the ones at the bottom.

The Alkali metals increase in reactivity going from top to bottom. The Alkaline Earth metals are denser and harder than others. Halogens are nonmetals. Noble Gasses are seperate and can combine together. Transition Metals have higher melting points than representative elements, Lathanide Elements are also called rare earth metals. Actinide Elements are radioactive and are the most synthetic.

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The Periodic Table: Crash Course Chemistry #4