Question

Elements of the same group have similar valance shell electronic configuration. Hence they exhibit similar chemical properties. But elements of the same period have different valencies.

Comment on the above statement.

Answer 1

Valency of an element determines its chemical reactivity.

Therefore, for all elements belonging to a particular group in the periodic table, the number of electrons in the outermost shell, that is the valence electrons will be the same.

Hence, all the elem in that group will show the same chemical reactivity. They will react with different elements in the same way and the molecular formula of their compounds will be similar.

Hence, they have the same chemical properties.