Question

For an element x, it is given that atomic number = 17 and mass number = 35. (3) (i) write the electronic configuration of the element x. (ii) find its valency. (iii) what will be the formula of the compound formed between x (above) and y having valency 3?

Answer 1

Answer:

i) 1s^2 2s^2 2p^6 3s^2 3p^5

ii) 7 valence electrons but valence is -1.

iii) YX3

It is Chlorine.