On the Periodic table, a period is a horizontal row of elements, while a group is a verticle row of elements.

All elements are placed into periods, but are not placed more specifically than groups. Everything in a group shares some of the same features, while everything in a period could be different state, different weight, different classification, etc.

Quantum mechanics places these periods together through electron shells.

Periods and groups share properties in two different ways. One is that elements in the same period share the same number of energy levels.

Periods Edit

References Edit