Question

How many of the following are possible: 1p, 2s, 3p, 3f, 3d?
A) 1
B) 2
C) 3
D) 4

Answer 1

Hint: The electronic configuration of an atom can be determined using the quantum numbers.
The possibility of orbits and orbitals and electronic arrangement in an orbital can be determined by Pauli's exclusion principle and the correlation among the quantum numbers.

Complete step by step answer:
Quantum numbers are essential as they are useful to determine the electronic configuration of an atom. There are a total four quantum numbers to describe the distribution of electrons in an atom. According to Pauli’s exclusion principle, each electron in an atom has a distinctive set of quantum numbers. The four quantum numbers are:
> Principal quantum number (n) - The electronic shell (orbit) is described by the principal quantum number(n). The value of n may be any integer. For n = 1, it is K shell, n = 2 it is L shell, n = 3 it is M shell and so on.
> Azimuthal (angular) quantum number (l)- The electronic subshell (orbital) is described by the azimuthal quantum number. It determines the angular distribution of an electron. For principal quantum number n, azimuthal quantum number l can take the value from 0 to (n - 1). For l = 0 it is s orbital, l = 1, it is p orbital, l = 2 it is d orbital, l = 3 it is f orbital and so on.
> Magnetic quantum number (m)- The number of orbitals and their orientation is determined by the magnetic quantum number (m). For a particular l value, m takes the value 2l + 1.
Spin quantum number (s) - It determines the spin of an electron.
For n = 1 , l can be 0 . So, we have one possible orbital for the first shell i.e. 1s.
Forn = 2 , l can be 0 and 1 . So, we have two possible orbitals for the second shell i.e. 2s and 2p.
Forn = 3 , l can be 0 ,1 and 2. So, we have three possible orbitals for the third shell i.e. 3s, 3p and 3d.
For n = 4 l can be 0 , 1 , 2 and 3. So, we have four possible orbitals for the fourth shell i.e. 4s, 4p, 4d and 4f.
That means 1p and 3f does not exist at all.
From the above option 2s, 3p and 3d orbitals exist.

Hence, the correct answer is (C).

Note: The energy, angular momentum and magnetic momentum depends on the quantum number n, l, s respectively.
The number of orbits, orbitals, orientation of electrons and shape of orbitals and spatial distribution of electrons can be determined by the quantum numbers.