How does electron configuration relate to the periodic table?
Electron configuration was used to group element with the same valance electron together. They also tend to have similar properties.
For simple explanation I will talk about only a representative element such as :
11Na : 1
19K : 1
you can see that Na and K was in the same group because their valance electron were in s orbital and only has 1 electron.
So if you do electron configuration with column 2 of periodic table you will also get 2 valance eleectrons in s orbital for Mg and Ca etc.