What is the kinetic energy of the photoelectrons emitted from a sodium surface ( = 2.9 *10^-¹⁹ J) when it is irradiated by photons with a wavelength of 350 nm? A) 2.9 *10^-¹⁹ J B) 5.7 *10^-¹⁹ J C) 0 J D) 2.8 *10^-¹⁹ J E) 3.6 * 10^-¹⁹ J

Question

Quizplus · Accepted Answer

The kinetic energy of photoelectrons can be calculated using the formula: 
KE = hν - φ 
where h is Planck's constant, ν is the frequency of the incident radiation, and φ is the work function (energy required to remove an electron from the surface).

We are given the wavelength (λ) of the incident radiation instead of frequency (ν), so we can convert it using: 
c = λν 
where c is the speed of light in vacuum.

ν = c/λ = (3.0 x 10^8 m/s)/(350 x 10^-9 m) = 8.57 x 10^14 Hz

Substituting the values, 
KE = (6.626 x 10^-34 J s) x (8.57 x 10^14 Hz) - (2.9 x 10^-19 J) 
KE = 2.8 x 10^-19 J

Therefore, the answer is D) 2.8 x 10^-19 J.

What Is the Kinetic Energy of the Photoelectrons Emitted from a Sodium