What is the maximum number of electrons allowed in the third energy level

18 electrons allowed in the 3rd energy level

The maximum number of electron in the first energy level (n = 1) is 2 (1)2 = 2 electrons. The maximum number of electron in the second energy level (n = 2) is 2 (2)2 = 8 electrons. The maximum number of electron in the third energy level (n = 3) is 2 (3)2 = 18 electrons etc ...

each chemical family is represented as a group or column on the periodic table. based on chemical properties, there are 6 types of chemical families. group 1 represents alkali metals, group 2 represents alkaline earth metals, groups 3 to 12 represent transition metals, groups 13 to 16 represent non-metals and other metals, group 17 represents halogens and group 18 represents noble gases.