How many electrons are in the first 5 energy levels?

Answer 1

The formula for the number of electrons you can have in each shell is 2n^2 (2 times n squared) where n is the energy level (also called the Principal Quantum Number).

So,

L1 = 2 x (1x1) = 2

L2 = 2 x (2x2) = 8

L3 = 2 x (3x3) = 18

L4 = 2 x (4x4) = 32

L5 = 2 x (5x5) = 50

So, 2 + 8 + 18 + 32 + 50 = 110.

Note that the above tells the maximum number, not necessarily the number for a particular element. An element can move on to another (higher) shell without having completely filled a lower shell. To find out for sure about a particular element, you need to consult an electron configuration table for that element.

Answer 2

The first energy level contains 2 electrons, the second level contains 8 electrons, the third level contains 18 electrons, the fourth level contains 32 electrons, and the fifth level contains 50 electrons. This is calculated using the formula 2n^2, where n is the energy level.