1. The Periodic Table of Elements

2. Russian scientist Dimitri Mendeleev was the first person who figured out that a pattern existed.

3. The Periodic Table of Elements Russian scientist Dimitri Mendeleev was the first person who figured out that a pattern existed. The word periodic means “a regular, repeated pattern.”

4. The Periodic Table of Elements Russian scientist Dimitri Mendeleev was the first person who figured out that a pattern existed. The word periodic means “a regular, repeated pattern.” As you move across the table from left to right, the properties of the elements change in a predictable manner.