Question

an element has atomic number of 11 and its mass number is 23. what is the arrangement of electrons in the Shell . state nuclear composition of an atom of the element.

Answer 1

No.of electrons in an atom is equal to atomic number of the element .

So no.of electrons in sodium is 11.

Secondly, no.of neutrons = mass number - no.of protons.

As protons are equal to electrons so 23 -11 = 12.

So sodium contains 12 neutrons 11 protons and 11 electrons

Answer 2

The element is SODIUM.

I have only written it for your understanding.

The arrangement of electrons in the shell is :- 2,8,1

No. Of protons- 11

No.of electrons - 11

No. Of neutrons - 12.