Question

The $n + 1$ value for the 3p-energy level is:
(A) 4
(B) 7
(C) 3
(D) 1

Answer 1

To find out the value of $n + 1$ we need to first understand the concept of quantum numbers. Quantum number is a simple phenomenon which explains the position of an electron in an atom according to principle shell, subshell, magnetic moment and spin.

Complete step by step answer:
Quantum number is explained in four major parts that are described below:
Principle quantum number: the principal quantum number defines the shell of the electron or its energy level. It is denoted by $n$ , and it starts from 1 to the ${n^{th}}$ shell where the valence electron is present.
Azimuthal quantum number: it is also known as the angular momentum quantum number, it is denoted by $l$ . It provides the value of the angular momentum and the subshell in which the electron is present. It starts from 0 to $n - 1$ , where each number stands for a different subshell, 0 for $s$ , 1 for $p$ , 2 for $d$ and so on.
Magnetic quantum number: the magnetic quantum number is denoted by ${m_l}$ . It provides the orbital of an electron within the subshell and also provides momentum along the axis. It’s calculated by using formula $2l + 1$ , and ranges from – to l with integers between them.
Spin quantum number: the spin quantum number is denoted as ${m_s}$ . It provides the spin of the electron. It has two values +1/2 and -1/2.
From the following information we have to find value of $n + 1$ for energy level 3-p the value of $n$ for 3-p is 3 then the value of $n = 1$ is ;
$\Rightarrow$ $3 + 1$
$\Rightarrow$ $4$
Correct option is (A).

Note:
To describe the complete exact position of the electron in an atom we use quantum numbers, now for an electron we cannot find momentum and position of electron accurately both at the same time, there always be uncertainty in either one of them.