Question

What is subshells?

Answer 1

In an atom shells are the circular paths around the nucleus of an atom along which the electrons traverse. (According to Bohr Model). The shells are represented by principal quantum number , n. And each shell are again divided into number of subshells.

There are four sub-shells - s , p , d ,f .

For example, the first shell consists of only one sub-shell that is s.
In the second shell there are two sub-shells- s and p .In the third shell there are three sub-shells - s, p , d .The rest of the shells consist of all four sub-shells - s , p , d , f .

A subshell is the set of states defined by azimuthal quantum number, l, within a shell. The values l = 0, 1, 2, 3 correspond s, p, d and f subshells, respectively. The maximum number of electrons which can occupy a subshell is given by 2(2l + 1). This gives two electrons in an s subshell, six electrons in a p subshell, ten electrons in a d subshell and fourteen electrons in an f subshell.
So on summarising,

• All electrons that have the same value for n (the principle quantum number) are in the same shell
• Within a shell (same n), all electrons that share the same l (the angular momentum quantum number, or orbital shape) are in the same sub-shell.