Question

What is the wavelength (angstroms) of a photon that has an energy of 5.69 × 10-17 j?

Answer 1

E = hc / λ 

Rearranging to get the wavelength (lambda):
λ = hc / E 
λ = 6.63x10^-34 Js x 3.00x10^8 m/s / 5.69x10^-17J 
λ = 3.50x10^-9 m 

3.5x10^-9 m x (100 cm / 1 m) x (1x10^8 Å / 1 cm) = 35 Å 

Answer 2

Answer: The correct answer is $\lambda= 35\AA$.

Explanation:

The expression for the relation between the energy of the wave and the wavelength is as follows;

$E=\frac{hc}{\lambda }$

Here, E is the energy of the wave, h is Planck's constant, c is the speed of the light and $\lambda$ is the wavelength of the wave.

It is given in the problem that the energy of the photon is $5.86\times 10^{-17} J$.

Put c= $3\times 10^{8} meter per second$, $h=6.63\times 10^{-34} kg square meter second$ and

$5.69\times 10^{-17}=\frac{(6.63\times 10^{-34})(3\times 10^{8})}{\lambda }$

$\lambda= 3.5\times 10^{-9}$

Convert the value of the wavelength into angstrom.

$1 \AA = 10^{-10} m$

$\lambda= \frac{3.5\times 10^{-9}m}{10^{-10}\AA }$

$\lambda= 35\AA$

Therefore, the wavelength of a photon is $\lambda= 35\AA$.