Which of the following shows the prefixes in order from smallest to largest? a) micro milli centi b) centi milli micro c) deca deci milli d) mega milli micro

A) micro milli centi

A) micro, milli, and centi are from smallest to largest.

Being in group one we know it has 1 valence electron, is highly reactive to halogens, and based on the fact it is in period 2 we know it has 2 energy levels, 1 being full. We know this because it applies to everything in group one except for the part about energy level which is based on period.