Answer:
8
Explanation:
It increases going up, because atom size is smaller, with greater energy levels; going right to left decreases, because they will have smaller charges when going through right to left.
Then, Calcium (Ca) is non-metal that reacts with Nitrogen (N), a non-metal. When 2 non-metal elements become a compound, it's covalent. Therefore, the bond between both of the elements are covalent.