Based on their formulas which of these compounds is not likely to be an ionic compound: KBr, SO2, or AlCl3? Explain.

SO2 is not likely to be ionic.

An ionic bond is most commonly formed between a metal and a non-metal.

K (potassium) and Br (bromine) are a metal and non-metal pair.

Al (aluminum) and Cl (chlorine) are a metal and non-metal pair.

S (sulfur) and O (oxygen) are both non-metals, and likely formed a covalent bond instead of an ionic bond, which is common for two non-metals.

SO2, since it is made of two non-metals.