Respuesta :

It's 6.

2(NH4)3PO4

The three outside the parenthesis means 3 NH4 groups. The coefficient of 2 means two entire formula units of 2(NH4)3PO4

That's 6 NH4 groups (2 x 3) making 6 N atoms.

How many H atoms? 4 x 3 x 2 = 24

2 P and 8 O