Each electron iii an atom is described by a set of three numbers called Quantum numbers.
1) Principal quantum number (n) : It is used to know the size and energy of the main shell The values of ‘n’ are 1, 2, 3 ….. energy of the shell, n = 1 < energy of the Shell n = 2.
2) Angular momentum of quantum number (l) :
It is used to know the shape of a particular sub shell. The values of ‘l’ are 0, 1, 2, 3
l = 0 = s orbital = spherical in shape
l = 1 = p orbital = dumbel in shape
l = 2 = d orbital = double dumbel Shape
3) i) Magnetic quantum number (ml) : It is used to describe the orientation of the orbital in space relative to the other orbitals in the atom.
The values of mt are – ‘l’ to ’+l’ including zero,
ii) Spin quantum number (m ) : It is used to know the orientation of the spins of electrons. The values of ms are +1/2 and – 1/2.
