Question

As the value of $n$ (number of the orbit) increases, the difference of energy between two consecutive energy levels,

• A. Remains the same
• B. Increases
• C. Decreases
• D. Sometimes increases and sometime decreases

Answer 1

The correct option is C Decreases

Consider two orbits $n_1$ and $n_2$
The energy of an electron, in electron-volt, in these orbits is given by,

$E_{n_1}=-\frac{13.6}{n_1^2}$
$E_{n_2}=-\frac{13.6}{n_2^2}$

So, the difference between these energy levels is,

$E_{n_1}-E_{n_2}=-13.6(\frac{1}{n_1^2}-\frac{1}{n_2^2})$

As the values of $n_1$ and $n_2$ increase, the value of $(\frac{1}{n_1^2}-\frac{1}{n_2^2})$ decreases. This can be verified by trial and error method.

Hence, $\left(C\right)$ is the correct answer.

Why this Question? This question is based on the concept of effect of change in $n$ on difference of energy levels.