Back to Questions
NEET Chemistry
QUESTION #7371
Question 1
The energy (in joules) of light with wavelength 45 nm is: (Given: \(h = 6.63 \times 10^{-34}\) Js, \(c = 3 \times 10^8\) ms\(^{-1}\))
Correct Answer Explanation
Formula: \(E = \dfrac{hc}{\lambda}\)
\(E = \dfrac{6.63 \times 10^{-34} \times 3 \times 10^8}{45 \times 10^{-9}}\)
\(= \dfrac{19.89 \times 10^{-26}}{45 \times 10^{-9}}\)
\(= \dfrac{19.89}{45} \times 10^{-17}\)
\(= 0.442 \times 10^{-17} = 4.42 \times 10^{-18}\) J
This energy (in UV range) is enough to ionise hydrogen from ground state (\(13.6\) eV \(= 2.18 \times 10^{-18}\) J).
\(E = \dfrac{6.63 \times 10^{-34} \times 3 \times 10^8}{45 \times 10^{-9}}\)
\(= \dfrac{19.89 \times 10^{-26}}{45 \times 10^{-9}}\)
\(= \dfrac{19.89}{45} \times 10^{-17}\)
\(= 0.442 \times 10^{-17} = 4.42 \times 10^{-18}\) J
This energy (in UV range) is enough to ionise hydrogen from ground state (\(13.6\) eV \(= 2.18 \times 10^{-18}\) J).
Sign in to join the conversation and share your thoughts.
Log In to Comment