Question

The formula unit CsO, ALS,RbI, or BeCl is neutral

Answer 1

The ionization energies must cancel out. (The +/- numbers in the top right corner of an element of the periodic table). So they must cancel out to create 0 (+1/-1). The neutral one will be the only one to cancel out.

Answer 2

RbI

Step-by-step explanation:

Let is carefully look at the charges on each option.

Rb is in group one of the periodic table, therefore it has a charge of +1. Iodine is in group seventeen of the periodic table hence it has a charge of -1. The two charges cancel out thereby leaving a neutral formula unit. That is RbI has a net charge of 1+(-1)=0. RbI is neutral.

None of the other options or remaining choices end up being neutral. Therefore the correct answer is RbI.