What types of atoms typically form covalent bonds? A. Metals with nonmetals, because their difference in electronegativity is above 1.7
B. Metals with nonmetals, because their difference in electronegativity is below 1.7
C. Nonmetals with nonmetals, because they're difference in electronegativity is above 1.7
D. Nonmetals with nonmetals, because of difference in electronegativity is below 1.7

D. Nonmetals with nonmetals, because of difference in electronegativity is below 1.7

Explanation:

The types of atoms that typically form covalent bonds are non-metals with non-metals because of the difference in their electronegativity which is below 1.7.

In some instances, the difference can even be zero when dealing with homonuclear substances.

answer; i believe that the correct answer is (a) potassium(k)

i believe you are right for all except the 3rd ( look at sqdancefan his answer is much better)