Question

What are the shells around the nucleus? K, L, M, N, O, P are the shells around the nucleus of an atom. Which shell is (a) nearest to the nucleus and (b) farthest from the nucleus?

Answer 1

Shells: Shells or orbits are the circular paths around the nucleus in an atom in which the electrons revolve.

• Every shell can accommodate a fixed number of electrons in it given by 2n² where n= serial number of the orbit. This was given by Bohr-Bury and known as Bohr-Bury scheme.
• Every shell is associated with a fixed amount of energy and known as energy levels.

(a) Shell which is the nearest to the nucleus is K

• Shells are numbered starting from the closest to the nucleus and outwards.
• So the first shell lies closest to the nucleus. First shell is also named as K shell.
• The first or the K shell has the lowest amount of energy associated with it and is filled the first.

(b) Shell which is the farthest from the nucleus is P

• The last shell will be the farthest from the nucleus.
• Out of all the shells given here, P shell has the highest amount of energy associated with it and is filled the last.