Element A has 2 electrons in its M shell. Element B has atomic number 7.
(a) Write equations to show how A and B form ions.
(b) If B is a diatomic gas, write the equation for the direct combination of A and B to form a compound.
(c) If the compound formed between A and B is melted and an electric current is passed through the molten compound, the element A will be obtained at the ............. and B at the ............ of the electrolytic cell.
A has two electrons in M shell i.e., A has valency 2 (metal), and the electronic configuration of B(7) is 2, 5 i.e., B has valency 3 (non-metal).
(a) A ⟶ A2+ + 2e-
B + 3e- ⟶ B3-
(b) 3A + B2 ⟶ A3B2
(c) Element A will be obtained at the Cathode and B at the Anode of the electrolytic cell.
Reason — As A is a cation, so it is attracted towards cathode as cathode is negatively charged. B is an anion so it is attracted towards anode as anode is positively charged.