How many sublevels, orbitals and electrons can be present in the K- shell of an atom?

 

In an atom, electrons are located in different energy levels outside the nucleus. In the case of the K-shell or energy level, n = 1. These shells or energy levels are divided into sub-energy levels. The sub-energy level is denoted by "l". The value of "l" ranges from zero (0) to (n- 1).

The sub-energy levels are further divided into different orbitals. In different orbitals, the electrons are arranged in three dimensions. This is called the magnetic quantum number (m). The value of m ranges from zero (0) to ± l.

If n = 1 for the K-shell,

For l = 0, the 1s-sub-energy level will be,

For l = 0, m = 0. That is, only 1s orbitals are possible in the K-shell.

Again, we know from the spin quantum number (s), that an orbital can hold a maximum of two electrons.

So the K-shell can hold

= 1x 2 = 2 electrons.

Therefore, the K-shell can hold one sublevel and two electrons.

(If l = 0, it is the s- sublevel, if l = 1, it is the p- sublevel, if l = 2, it is the d- sublevel, if l = 3, it is the f- sublevel.)