Question

The table below gives the number of protons and neutrons in element G,H,I and J.

Element	G	H	I	J
Number of protons	3	17	19	19
Number of neutrons	4	20	18	22

1. Which atoms isotopes of the same element?
2. Which atoms have the same mass number 
3. Write formula of the compound formed between G and H 

Answer 1

1. I and J
2. H and I
3. 2G(s) + H₂(g) → 2GH(g)
   Or
   2Li(s) + Cl₂(g) → 2LiCl(s)