G = {7, 8} and H = {5, 4, 2}
We know that the Cartesian product P x Q of two non-empty sets P and Q is defined as :
P x Q = {(p, q): p∈P, q ∈Q}
∴G x H = {(7, 5), (7, 4), (7, 2), (8, 5), (8, 4), (8, 2)}
H x G = {(5, 7), (5, 8), (4, 7), (4, 8), (2, 7), (2, 8)}
What inference do you draw about the behaviour of Ag+ and Cu2+ from these reactions?