which of these is a nonpolar covalant bond?

Question

HCL
CaO
NH3
O2

Answer 1

O2

Answer 2

Let's do the process of elimination. HCl (that's a small l in the chlorine) and CaO are ionic.

That leaves NH3 and O2 as having covalent bonds. For a bond to be non-polar, the different atoms have to have the same (or near same) electronegativity, or ability to attract electrons. It's one atom attracting electrons more than another that majkes the bond polar (i.e., it has partially positive and negative poles).

Even without knowing the electronegativity of N and H (they are different), you've got a sure bet that the oxygen-oxygen bond in O2 must be non-polar, as one oxygen is not going to be any more electronegative than another.

So O2 it is.

Answer 3

o2