Question

Which of the following electronic transitions in a hydrogen atom will require the largest amount of energy?

• A. From $n = \infty$ to $n = 1$
• B. From $n = 1$ to $n = 2$
• C. From $n = 2$ to $n = 5$
• D. From $n = 5$ to $n = 1$

Answer 1

Answer: (B)

As ‘n’ increases the difference in energy between successive orbits decreases
From $n = 1$ to $n=2$, difference in energy,
$\Delta E=E_{2}-E_{1}=10.2\,eV$
From $n=1$ to $n= \infty$, $\Delta E=E_{\infty}-E_{1}=0-(13.6)=13.6\,eV$
$\therefore $ From $n=2$ to any higher stationary state, $\Delta E \le$ $(13.6-10.2=3.4\,eV)$
In option $(1)$ and $(4)$, energy is released