Explore BrainMass
Share

# Ejecting Electrons with Light

This content was COPIED from BrainMass.com - View the original, and get the already-completed solution here!

The minimum frequency of light needed to eject electrons from a metal is called the threshold.

Find the minimum energy needed to eject electrons from a metal with a threshold frequency of 3.27*10^14s^-1.

With what kinetic energy will electrons be ejected when this metal is exposed to light with a wavelength of lamda = 245 nm?

KE_electron = _________ J

HINT:
Energy is related to frequency via E = hv.

The energy of the ejected electron is the difference between the minimum required energy and the energy of the light. You're given the wavelength of the light (lambda = 245 nm) which you'll need to convert to energy using E = hc/lambda.

Recall that h is Planck's constant (h = 6.626*10^-34 J*s) and c is the speed of light (c=2.998*10^8 m/s).

https://brainmass.com/chemistry/modern-quantum-theory/ejecting-electrons-light-504184

#### Solution Preview

1. Solving for the minimum energy needed to eject the electron:
E = h?
E = (6.626 × 10-34 J·s)(3.27 x 1014/s)
E = 2.17 x 10-19 J

2. To solve for the ...

#### Solution Summary

This solution provides calculations for various questions involving ejecting electrons with light.

\$2.19