# Question cf092

Dec 5, 2016

You can use arbitrary values of ΔEN to classify the bond type, but you can also use your knowledge of molecular geometry and structure to predict this as well.

#### Explanation:

In arbitrary units, the Pauling scale:

Nonpolar covalent bonds when, ΔEN<0.5 
Polar covalent bonds when,  0.5 < ΔEN < 1.7
Ionic bonds when,  ΔEN>1.7

Of course, you need some sort of chart or table to do this (mainly the Pauling scale values), but if you do not have a chart with electronegativity values to compare, consider this:

If the compound is ionic (metal + nonmetal constituents) the bond formed will be ionic.

If the compound is molecular, the bond formed could be a polar covalent bond or a nonpolar covalent bond depending on "close" the bonded species are on the periodic table.

As expected then, for diatomics, the bond is formed is nonpolar covalent. Such as ${F}_{2}$ or ${O}_{2}$.

But, the bond between two molecular species can sometimes be ionic, in the case of $B {F}_{3}$ for example - so be careful. It's best to use elctronegativity values to calculate ΔEN when you can.

You can find elctronegavity values here:
http://www.ptable.com/Property/Electronegativity