Give a definition of the period and group of chemical elements. How do the properties of chemical elements

Give a definition of the period and group of chemical elements. How do the properties of chemical elements and their compounds change in the group and period?

A period is a horizontal row of elements in the periodic table. The periods are small (1, 2, 3) and large (consist of two rows). Each period begins with an alkali metal and ends with an inert gas. In periods from left to right, metallic properties weaken, and non-metallic properties increase.
A group is a vertical row of elements, in the table there are 8. Each group consists of a main and a secondary (elements of only large periods) subgroups. In groups from top to bottom, non-metallic properties are weakened.