How to make into compounds to get a formula?

Li+: Br-, O2-, CN-, SO3^2-, PO3^3-,MnO4-
Cu:Br-, O2-, CN-, SO3^2-, PO3^3-,MnO4-
Pb2+:Br-, O2-, CN-, SO3^2-, PO3^3-,MnO4-
Ca2+:Br-, O2-, CN-, SO3^2-, PO3^3-,MnO4-
Al3+:Br-, O2-, CN-, SO3^2-, PO3^3-,MnO4-
Cr5+:Br-, O2-, CN-, SO3^2-, PO3^3-,MnO4-
Pb4+:Br-, O2-, CN-, SO3^2-, PO3^3-,MnO4-
Sn2+:Br-, O2-, CN-, SO3^2-, PO3^3-,MnO4-
Mn2+:Br-, O2-, CN-, SO3^2-, PO3^3-,MnO4-
Ag+:Br-, O2-, CN-, SO3^2-, PO3^3-,MnO4-
H+:Br-, O2-, CN-, SO3^2-, PO3^3-,MnO4-

To determine the formula of a compound formed between two ions, you need to find the combination that results in a neutral compound. In a neutral compound, the sum of the charges of the ions must be zero.

Let's go through the examples you provided and determine the formulas of compounds formed between each cation (positive ion) and anion (negative ion):

1. Lithium ion (Li+):
- Li+ can combine with Br- to form LiBr (lithium bromide).
- Li+ can combine with O2- to form Li2O (lithium oxide).
- Li+ can combine with CN- to form LiCN (lithium cyanide).
- Li+ can combine with SO3^2- to form Li2SO3 (lithium sulfite).
- Li+ can combine with PO3^3- to form Li3PO3 (lithium phosphite).
- Li+ can combine with MnO4- to form LiMnO4 (lithium permanganate).

2. Copper ion (Cu):
- Cu can combine with Br- to form CuBr (copper bromide).
- Cu can combine with O2- to form CuO (copper oxide).
- Cu can combine with CN- to form CuCN (copper cyanide).
- Cu can combine with SO3^2- to form CuSO3 (copper sulfite).
- Cu can combine with PO3^3- to form CuPO3 (copper phosphite).
- Cu can combine with MnO4- to form Cu(MnO4)2 (copper permanganate).

You can follow the same process for the rest of the examples by pairing each cation with the available anions and finding the combination that results in a neutral compound.