What is the greatest number of electrons in the first seven energy level

280 electrons

Explanation:

The number of electrons in each energy level are determine by using following formula:

2n²

Here "n' is the energy level. we will put the energy level number in place of "n" and number of electrons will easily found.

Principle energy levels number of electrons

1 2n² = 2 (1) ² = 2

2 2n² = 2 (2) ² = 8

3 2n² = 2 (3) ² = 18

4 2n² = 2 (4) ² = 32

5 2n² = 2 (5) ² = 50

6 2n² = 2 (6) ² = 72

7 2n² = 2 (7) ² = 98

So the total number of electrons in first seven energy levels will be the sum of the number of electrons in each energy levels.

2+8+18+32+50+72+98 = 280 electrons