Question

Based upon the valence numbers of the elements magnesium (2) and hydrogen (1), predict how many covalent bonds would form between these atoms to achieve the full complement of electrons in their outermost energy shells. based upon the valence numbers of the elements magnesium (2) and hydrogen (1), predict how many covalent bonds would form between these atoms to achieve the full complement of electrons in their outermost energy shells. one two three four

Answer 1

Magnesium is in the second group in the periodic table, which means that its outer shell is an s-orbital which contains 2 valence electrons.

Hydrogen also has an s-orbital as an outer shell but it only contains 1 valence electron. The electron dot diagram would look like this:

H· ·Mg· ·H

Each hydrogen shares one electron with magnesium and the magnesium shares one of its electrons with each hydrogen resulting in two covalent bonds.

H:Mg:H and this gives us the compounds MgH₂