An electron jumps from nth level to the first level .The correct statement(s) about H atomic is//are

Options

A. Number of spectrum lines `= (n(n-1))/(2)`
B. If `n = 4`number of spectrum lines `= 6`
C. Number of spectrum lines `= (n(n+1))/(2)`
D. If `n = 4` number of spectrum lines `= 10`

Explanation

To solve the problem of an electron jumping from the nth energy level to the first level in a hydrogen atom and to determine the correct statements about the hydrogen atom, we can follow these steps:

### Step 1: Understand the Transition
An electron transitions from a higher energy level (n) to a lower energy level (n=1). This transition will result in the emission of energy in the form of light, which can be observed as spectral lines.

### Step 2: Identify the Formula for Spectral Lines
The number of spectral lines (N) formed during the transition from a higher level (n) to a lower level (n=1) can be calculated using the formula:
\[ N = \frac{(n_1 - n_2)(n_1 - n_2 + 1)}{2} \]
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