Which category does the ion po43- belong to?

Polytatomic anion, anion b/c charge is negative , poly atomic because theres more than one atom 

Polyatomic anion this is it hope it helps

The answer is the first option just took the test

The independent variable is the type of music.the dependent variable is the pulse rate.the intervening variable is the age of the subject.if the mother does not like rock, her pulse is likely to not increase.the same might be true for the sister.the friend may like rap and gets excited.to establish cause/effect relationship, all of the subjects must be consistent.hope i .