Question

Because polyatomic ions are made of covalently bonded atoms, do they behave like simple covalent bonded atoms?

Answer 1

No, they behave like simple ions.

Even though they are made of covalently bonded atoms, they have a charge. So they behave as ions.

See What are polyatomic ions?.

That makes it easy to balance equations that have polyatomic ions.

If we have to balance an equation like

(NH₄)₂SO₄ + Ba(NO₃)₂ → NH₄NO₃ + BaSO₄

we can mentally let NH₄ = M, SO₄ = X, and NO₃ = Y. Then the equation becomes

We balance this as

M₂X + BaY₂ → 2MY + BaX

When we put the symbols back in, we get

(NH₄)₂SO₄ + Ba(NO₃)₂ → 2NH₄NO₃ + BaSO₄

You will soon get used to it, and then you can do polyatomic ions in your head.