How many atoms are in (NH4)2SO4

What is the formula that this ionic compounds could form sr2+p3-o2-

Match the mixture with the substance// i really need on this guys (it’s a pic btw)

The diagin dilutepage 6 of 12a6a5(a)fluorine, chlorine, bromine and iodine are placed in the same group of theperiodic table.state the common name used to describe elements in this group.(i)state the group in which the elements are placed and explain whythey are placed in that group.(ii)which of the above named elements is a solid at roomtemperature and pressure?