Question

which is not correct order of energy for first, second and third orbit

Answer 1

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

Answer 2

ANSWER REFER TO ATTACHMENT

CORRECT ORDER OF ENERGY LEVELS IN ORBITS

BY AFBAU'S PRINCIPLE

THANKS