Concept of Shells and Subshells

Concept of Shells and Subshells

Atoms are the basic unit of matter. Earlier beliefs were proven wrong when more discoveries came into light. It is now known that atoms can be  subdivided into particles such as protons, neutrons and electrons. In the core of the atom, neutrons and protons make up the nucleus and stay inside. On the other hand, electrons are in constant movement around the nucleus. 

Electrons move only in a specified path around the nucleus, called shell, subshell, and orbital. While all three terms here denote the path of electron movement, they are used by electrons that differ in their quantum number and energy. 

What is a Shell?

A shell is the path of electrons to go around the atom’s nucleus. There are several shells around an atom having different energy levels. The shells are arranged in their increasing order around the nucleus. The shell having the least energy comes first and that with the highest energy is farthest from the nucleus. They are recognized as K, L, M, N, etc. 

Each shell can hold a number of electrons that are based on its principal quantum number (n). Its formula is 2n^2, where ‘n’ is the shell number. 

What is Subshell in Chemistry?

The subshell definition simply put is the minute path through which the electrons move within a shell. They are also arranged as per their energy from low to highest. They are also further divided as per their energy and electron holding capacity. 

What are Subshells?

The subshells are named according to their angular momentum quantum number. Thus, there are 4 kinds of subshells in a shell- s, p, d, f. The s subshell has the lowest energy followed by p, d, and f. They also have specific structure. The ‘s’ subshell has a spherical shape while the p has a dumbbell shape and d has a double-dumbbell shape. 

The characteristics of subshells are:

• The subshells are distributed based on the azimuthal quantum number which is noted as by ‘l’
• The maximum capacity of each subshell is calculated by the formula 2*(2l + 1)
• As per the formula, the subshells s, p, d, and f can carry only up to 2, 6, 10, and 14 electrons in them, respectively