Question

What is the color and wavelength of light with 2.88 x 10-19 J of energy?

Answer 1

Answer : The color and wavelength of light is red and $6.9\times 10^{-7}m$ respectively.

Explanation :

Given:

Energy = $2.88\times 10^{-18}J$

Now we have to determine the wavelength of light.

Formula used:

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

where,

E = energy

h = Planck's constant = $6.626\times 10^{-34}J.s$

c = speed of light = $3\times 10^8m/s$

$\lambda$ = wavelength of light

Now putting all the given values in this formula, we get:

$2.88\times 10^{-18}J=\frac{(6.626\times 10^{-34}J.s)\times (3\times 10^8m/s)}{\lambda}$

$\lambda=6.9\times 10^{-7}m$

From the electromagnetic spectrum we conclude that the color of the light will be red of wavelength $6.9\times 10^{-7}m$.

Therefore, the color and wavelength of light is red and $6.9\times 10^{-7}m$ respectively.