Dimitri Mendeleev

The Origins of the Periodic Table

The origins on the periodic table begin with the work of John Newlands and Dimitri Mendeleev.

Groups and Periods in the Periodic Table

Groups and Periods are the columns and rows of the periodic table. In this section you will explore how the periodic table was put together and the two main arrangement of the periodic table focusing on the groups and periods and metals and non metals.

Atomic Number of the Elements

The atomic number of the elements provides information on the number of protons in the nucleus.

Why is the Periodic Table so Important?

Why are There Gaps in the Periodic Table?

Gaps in the periodic table were first used by Dimtri Mendeleev when he could not find an element to fit the patterns of the groups and periods he was using. Mendeleev knew there would be undiscovered elements so used these gaps to prompt other scientists to start looking for them.

The Structure and Meaning of the Periodic Table: Groups

Groups in the periodic table are the columns where elements with similar properties are found grouped together.