26. Periodic Table Of Elements
- Invented By: Dimitri Mendeleev In 1869
Today, we do not look at the Periodic Table and automatically think of it as one of the world’s biggest scientific breakthroughs. Yet this is in error, as every element on the Periodic Table is massive to our everyday life. Of course, we did not discover all of these elements at the same time. It took quite a long time to put the elements together that we see today. There are 7 Rows, called periods, which have metals on the left with nonmetals on the right.

In the Columns, often called groups, elements with similar chemical behaviors will be present. 6 of the groups have internationally accepted names and assigned numbers. Those include the Halogens & Noble Gases, for example. Then there are 4 blocks that tell us of different atomic orbitals. Those you might see on the element chart include Oxygen, Hydrogen, Sodium, Mercury, Lead, Sulfur, Argon, and many more.