History of the Periodic Table

Question 1

What happened when all of the elements were put in order of relative atomic mass in the 1800’s?

Answer 1

Scientists began to notice periodic patterns in the properties of the elements.

Question 2

In 1869, how did Russian, Dmitri Mendeleev, arrange 50 or so named elements?

Answer 2

According to their properties and the properties of their compounds to make a Table of Elements.

Question 3

How did Mendeleev’s table place elements?

Answer 3

With similar chemical properties in the same vertical groups. He found he had to leave gaps in his table to make this work.

Question 4

What did the gaps in Mendeleev’s table allow him to do?

Answer 4

Predict the properties of undiscovered elements

Question 5

In the 1800’s what did scientists know about the structure of atoms?

Answer 5

Nothing - but they could measure the relative atomic mass of each element