Question

2p orbital have:
A.${\text{n}} = 1,{\text{l}} = 2$
B.${\text{n}} = 1,{\text{l}} = 0$
C.${\text{n}} = 2,{\text{l}} = 1$
D.${\text{n}} = 2,{\text{l}} = 0$

Answer 1

n represent the shell of electron and l represent the subshell of electron. Value of n and l is related as ${\text{l}} = 0{\text{ to }}\left( {{\text{n}} - 1} \right)$. n is known as principal quantum number and on the other hand, l is known as azimuthal quantum number.
Complete Answer:
Quantum number gives description of orbital and electron by designating them properly according to their properties. Each orbital in an atom is designated by a set of three quantum numbers and each electron is designated by a set of four quantum numbers.
Principal quantum number which is represented by n. it represents the name, size and energy of the shell to which the electron belongs. It indicated the distance of electrons from the nucleus. The value of the principal quantum number ranges from 1 to infinite. Greater value of n corresponds to greater distance of shell from nucleus and greater energy of shell.
Azimuthal quantum number is represented by l. It is also known as the angular quantum number. It represents the shape of the subshell and orbital. Value of l is between 0 to $\left( {{\text{n}} - 1} \right)$ . Value of l for various value of n is as follow:

n	${\text{l}} = 0{\text{ to }}\left( {{\text{n}} - 1} \right)$	Description
1	0	1s
2	0,1	2s,2p respectively
3	0,1,2	3s,3p,3d respectively
4	0,1,2,3	4s,4p,4d,4f respectively

Magnetic quantum number is represented by m. It represents the orientation of the orbital. Value of is equal to all integral values from $- {\text{l to }} + {\text{l}}$ including zero. Spin quantum number is represented by s. it represents the direction of electron spin around its own axis. Value of ${\text{s}} = \pm \dfrac{1}{2}$ .
Thus, as given in the question, 2p orbital have ${\text{n}} = 2,{\text{l}} = 1$ .

Thus, the correct option is C.

Note: If the value of n is same then the order of energy of the various subshells will be: ${\text{s}} < {\text{p}} < {\text{d}} < {\text{f}}$ and if the value of l is same but value of n is different, then the order of energy will be: $1{\text{s}} < 2{\text{s}} < 3{\text{s}} < 4{\text{s}}$ .