Question

Give two examples for each group.

Group 7A element

Answer 1

Modern periodic table:

• The modern periodic table is an arrangement of all the elements known in accordance with their increasing atomic number and recurring chemical properties.
• It is a tabular display of 118 chemical elements which consists of horizontal rows called periods and vertical columns are called groups.
• All elements in a group have the same number of valance electrons, and in period elements have the same number of electron shells.
• There are seven periods and eighteen groups in the modern periodic table.

Group 7A :

• This group is called halogens.
• They occupy the seventh column of the periodic table.
• They are highly electronegative non-metals their valance shell has a vacancy of one electron.
• Two examples of halogens are Fluorine ($\mathrm{F}$), Chlorine ($\mathrm{Cl}$).