Question

16. 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.​

Answer 1

(a) As far as element A is concerned its atomic number is 12

So it will form ion as

A -----> A^+2 +2e

For element B

B -----> B^+3 + 3e

(b) 3A + B2 -----> A3B2

(c) element A will be obtained at cathode and element B will be obtained at anode.

I hope this helps.

Incase you still have doubt feel free to ask.

Answer 2

Answer:

a) A =2+ve and B= 3-ve

b) A3B2 ( electrovalent compound)

c) cathode , anode

Explanation:

a)As A has the valency of 2 and B has valency of 3

b) A 2+ve + B 3-ve = A3B2

c) cations migrate towards cathode (-ve charged plate ) and anions migrate towards (+ve charged plate ) , A=Cation and B =Anion