Electronic Configurations

Question 1

What is the order of electron shells?

Answer 1

1 - 2
2 - 8
3 - 8

The lowest level always have the lowest energy

Question 2

How can you tell how many electrons an element has?

Answer 2

Work it out by groups and periods.

Groups tell you how many electrons in the outer shell
Periods tell you have many shells. According to the period eg 1 hydrogen