Atomic Structure Question 375
Question: The values of Planck’s constant is $ 6.63\times {10^{-34}} $ Js. The velocity of light is $ 3.0\times 10^{8}m{s^{-1}} $ . Which value is closest to the wavelength in nanometres of a quantum of light with frequency of $ 8\times 10^{15}{s^{-1}} $ -
Options:
A) $ 5\times {10^{-18}} $
B) $ 4\times 10^{1} $
C) $ 3\times 10^{7} $
D) $ 2\times {10^{-25}} $
Show Answer
Answer:
Correct Answer: B
Solution:
- $ E=hv=\frac{ch}{\lambda };,and,v=\frac{c}{\lambda } $
$ 8\times 10^{15}=\frac{3.0\times 10^{8}}{\lambda } $
$ \therefore \lambda =\frac{3.0\times 10^{8}}{8\times 10^{15}}=0.37\times {10^{-7}} $
$ =37.5\times {10^{-9}}m=4\times {10^{-1}}nm $
