1. The Periodic Table 1 2 3 4 5 6 7

2. When alchemists first started studying the elements, they just put them in a list from lightest to heaviest.

3. Dmitri Mendeleev was a Russian chemist who noticed that if you looked at the elements in that list and how they acted, you saw repeating patterns.

4. He called this pattern “Periodicity”

5. He then claimed that he had a dream where the elements were all flying around started to line up in the pattern that we see today in the Periodic Table.

6. Did the table that he came up with have all of the elements?

7. NO! There were elements that were not yet discovered in his time. He just left blanks in his table and predicted that they would be found in the future.

8. Parts of the Periodic Table Groups –Are the columns (up & down) –Are numbered 1-18 –Contain elements with similar electron configurations = similar chemical properties Periods –Are the rows (   ) –Are numbered 1-7 –Contain elements with the same number of energy levels

9. Information on Periodic Tables