Question

what the number of energy level?​

Answer 1

Answer:

Energy Levels

Each principal energy level can contain up to 2n2 electrons, where n is the number of the level. Thus, the first level can contain up to 2 electrons, 2(12) = 2; the second up to 8 electrons, 2(22) = 8; the third up to 18, 2(32) = 18; and so on

Answer 2

Each principal energy level can contain up to 2n2 electrons, where n is the number of the level.

Thus, the first level can contain up to 2 electrons, 

2(12) = 2; the second up to 8 electrons, 2(22) = 8;

the third up to 18, 2(32) = 18; and so on.