Electronegativity is a chemical property which describes how well an atom can attract an electron to itself. Values for electronegativity run from 0 to 4. The difference in electronegativity (ΔEN) is used to predict whether a bond between atoms will be ionic or covalent. It can also be used to predict if the resulting molecule will be polar or nonpolar.

If a bond was made between the two atoms shown below, would the bond be (1) covalent, i.e. ΔEN = ≤ 0.4, (2) polar covalent i.e. ΔEN > 0.4 and ≤2.0, or (3) ionic, i.e. ΔEN > 2.0? Enter 1 for covalent, 2 for polar covalent, 3 for ionic.

protactinium, francium