Atomic Structure - Result Question 111
87. Calculate the wavelength in Angstroms of the photon that is emitted when an electron in the Bohr’s orbit, $n=2$ returns to the orbit, $n=1$ in the hydrogen atom. The ionisation potential of the ground state hydrogen atom is $2.17 \times 10^{-11}$ erg per atom.
(1982, 4M)
Show Answer
Answer:
Correct Answer: 87. $(1220$ $Å)$
Solution:
- Ionisation potential of $H$-like species
$=E _1=2.17 \times 10^{-11} erg$
$\begin{aligned} \Rightarrow \Delta E & =2.17 \times 10^{-11}\left(1-\frac{1}{2^{2}}\right) \times 10^{-7} J \\ & =1.6275 \times 10^{-18} J \Rightarrow \lambda=\frac{h c}{\Delta E} \\ & =\frac{6.625 \times 10^{-34} \times 3 \times 10^{8}}{1.6275 \times 10^{-18}} m \\ & =122 \times 10^{-9} m=1220 Å \end{aligned}$
BETA
