Question

Define periods and groups of the modern periodic table.

Hint:

The periodic table is organized into periods (rows) and groups (columns), with elements in the same group exhibiting similar chemical behaviors due to the same number of valence electrons.

Answer 1

Periods: A period is a horizontal row in the periodic table. There are 7 periods in the modern periodic table. The elements in a period have the same number of electron shells or energy levels. As we move across a period from left to right, the atomic number increases, and the properties of elements gradually change. Groups: A group is a vertical column in the periodic table. There are 18 groups in the modern periodic table. Elements in the same group have the same number of valence electrons, which gives them similar chemical properties. For example, Group 1 contains the alkali metals, and Group 17 contains the halogens. - Periods: Periods are horizontal rows in the periodic table. Elements in the same period have the same number of electron shells. As we move from left to right across a period, the elements go from metallic to non-metallic character. - Groups: Groups are vertical columns in the periodic table. Elements in the same group have similar chemical properties due to having the same number of valence electrons. For example, Group 1 elements are all highly reactive metals, while Group 17 elements (halogens) are all non-metals.