Question

Ionisation potential of hydrogen atom is 13.6 eV. Hydrogen atom on the ground state rarely excited by monochromatic radiation of photon 12.1 eV. The special line emitted by a hydrogen atom according to Bohr's theory will be :

• A. One
• B. Two
• C. Three
• D. Four

Answer 1

The correct option is C Three

Energy of ground state of electron $=-13.6EeV$

Energy required to excite to $n^{th}$ state $=12.1eV=13.6eV\times (\frac{1}{1^2}-\frac{1}{n^2})$

$⟹n=3$

Thus, the lines will be emitted when transition will be from $3$ to $1$.

The lines would be $3\to 1$, $3\to 2$ and $2\to 1$.

Hence, there would be three lines.