Calculate the energy of a light with a wavelength of 142 nm.

E =  0.14 ×10⁻¹⁷ J

Explanation:

Given data:

Wavelength of light = 142 nm (142 ×10⁻⁹ m)

Energy of light = ?

Solution:

Formula:

E = hc/λ

h = plancks constant = 6.63×10⁻³⁴ Js

c = speed of light = 3×10⁸ m/s

by putting values

E = 6.63×10⁻³⁴ Js × 3×10⁸ m/s / 142 ×10⁻⁹ m

E = 19.89×10⁻²⁶ J.m/ 142 ×10⁻⁹ m

E =  0.14 ×10⁻¹⁷ J

nacl is added to the aqueous of what? ? in order to get a proper answer you have to specify the exact composition of the aqueous solution.