Question

A hydrogen atom is in ground state. Then to get six lines in emission spectrum, wavelength of incident radiation should be

• A. 800 \(\mathring{A}\)
• B. 825 \(\mathring{A}\)
• C. 975 \(\mathring{A}\)
• D. 1025 \(\mathring{A}\)

Hint:

The number of lines in the hydrogen spectrum depends on the transitions of electrons between different energy levels. The wavelength of incident radiation determines these transitions.

Answer 1

The Correct Option is A

Step 1: Understanding emission lines.
The hydrogen atom emits spectral lines when an electron moves from a higher energy level to a lower one. To get six lines in the emission spectrum, the wavelength of incident radiation must excite the electron to the required energy level.
Step 2: Using the Balmer formula.
For hydrogen, the wavelength of incident radiation that produces six lines is given by \( \lambda = 800 \, \mathring{A} \), which corresponds to the excitation from the ground state to higher levels.
Final Answer: \[ \boxed{800 \, \mathring{A}} \]