Question

Calculate the approximates energy of a photon given that wavelength of photon is 2 nm and Planck constant $h$ is $6.6\times {10}^{-34}Js$.

• A. $4\times {10}^{-51}J$
• B. $1\times {10}^{-34}J$
• C. $1\times {10}^{-16}J$
• D. $1\times {10}^{34}J$
• E. $2\times {10}^{-50}J$

Answer 1

The correct option is C $1\times {10}^{-16}J$

The energy of photon is $E=h\nu =\frac{hc}{\lambda }=\frac{(6.6\times {10}^{-34})(3\times {10}^8)}{2\times {10}^{-9}}=9.9\times {10}^{-17}J\sim {10}^{-16}J$

Thus, the option C will correct.