Question

An element belonging to the third period and group third A(13) of the periodic table.

State:

(a) The no. of valence electrons,

(b) The valency

(c) If it is a metal or non-metal

(d) The name of the element

Answer 1

As it is stated that element belongs to the third period and from 13 groups so we can calculate the atomic no. of that element.

In period 1 only two elements are present and in period 2 total of eight elements are present again in the third period eight elements are present.

So, by this, we can understand that the atomic no of the element which is present in the third period and 13 group is 13 and it is aluminum.

(a) To know about valence electrons firstly we have to get their electronic configuration that is:

Al: 2, 8, 3

So, valence electrons are 3

(b) Its valency is +3 because it has to lose 3 electrons to get stable.

(c) As it is losing electrons so it is metal as loss of an electron is a property of metals.

(d) Name of the element is Aluminium.