Question

In which transition a hydrogen atom, photons of lowest frequency are emitted?

• A. n = 4 to n = 3
• B. n = 4 to n = 2
• C. speed of an electron in the $4^{th}$ orbit of hydrogen
• D. n = 3 to n = 1

Answer 1

The correct option is A n = 4 to n = 3

Frequency of an emission is given by, $v=\frac{△E}{h}$ $△E:$ Transition energy H: planck's in constant

The lower the energy ($△E$) the lower would be frequency of photon.

also $△E=R(\frac{1}{n_1^2}-\frac{1}{n_2^2}),$ So reign the exited state, lower the energy

From are given option, $n\ne 4$ to $n\doteq 3$ releases lowest Energy

and so emits lowest frequency radiation.