Answer:
Calcium
Explanation:
Hi!
So, the best way to solve this is with a period table with all of the sublevels labeled. (check below)
So the s sublevel starts at 1s which is Hydrogen. If you go down 4 rows, or periods, you get to sublevels 4s. As you should know, as you go across groups/columns, the valence electrons get higher. So the element that you are looking for has 2 valence electrons. So, the element you are looking for should be 4 down and 1 right of Hydrogen which is: Calcium
I hope I helped and have a wonderful evening!
