Which element has a 4s sublevel with 2 electrons for its outermost electrons.

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!

we can conclude that the melting point of table salt is above room temperature (it's actually 801 deg c). the melting point of mercury must be below room temperature (- 39 deg c).