Hydrogen atom is bombarded with electrons accelerated through a potential different of V , which causes excitation of hydrogen atoms. If the experiment is being formed at T = 0 K . The minimum potential difference needed to observe any Balmer series lines in the emission spectra will be α 10 V , where α = _________.(Write the value to the nearest integer)

Step-by-step solution

For minimum potential difference, electron has to make transition from n = 3 to n = 2 state but first electron has to reach to n = 3 state from ground state. So, energy of bombarding electron should be equal to energy difference of n = 3 and n = 1 state. Δ E = 13 . 6 1 - 1 3 2 e = e V ⇒ 13 . 6 × 8 9 = V ⇒ V = 12 . 09 V ≈ 12 . 1 V So, α = 121 .