Question

An element ‘A’ has atomic number 11, name the period and group number to which it belongs.

Answer 1

Answer:

it belongs to group 1 period 3

Answer 2

Answer:

So, the element A, which has its atomic number as 11 belongs to Group 1 (1A) on the Periodic Table.  

Explanation:

Here the element is having its atomic number = 11. So now if we look at the periodic table the element that has atomic number 11 is Na (Sodium).

So let us assume that this element is Sodium (this makes the question easy to understand).

It is certain that as far as Sodium is concerned, its atomic number is 11. This element is an Alkali metal. Sodium has its electronic configuration as 2,8,1. This means that its outer most orbit has only one electron.  

The valence of Sodium is 1. Now as we know its valence, so we also know that this element is placed in Group 1 in the PT.

All elements that have single electron in its outer most orbit (shell) are placed in group 1 on the Periodic Table.

So the element that we are discussing here is having Group 1.

Now coming to the period,, again we already know that the element belongs to the Alkali metal and these are elements that are placed in Group 1 and Period 1A on the Periodic Table.  

The element discussed here belongs to the Period 1A.

So, the element A, which has its atomic number as 11 belongs to Group 1 (1A) on the Periodic Table.