Question

Elements X and Y have atomic numbers 13 and 8, respectively. The chemical formula of the compound formed will be:

Options

• XY

• X₃Y₃

• X₂Y₃

• X₃Y₂

Answer 1

X₂Y₃

Explanation:

Element X (Atomic number 13) has the electronic configuration 2, 8, 3, so its valency is 3.

Element Y (Atomic number 8) has the electronic configuration 2, 6, so its valency is 8 − 6 = 2.

Using the criss-cross method, the valencies combine to form the formula X₂Y₃.