Conceptual Physics (12th Edition)

Published by Addison-Wesley
ISBN 10: 0321909100
ISBN 13: 978-0-32190-910-7

Chapter 31 - Think and Explain - Page 598-599: 35


The ejection of an electron depends on the interaction of one photon with an electron. Photons of red light are less energetic than blue photons.

Work Step by Step

For photons, E = hf, where E is the energy, h is Planck's constant, and f is the photon's vibrational frequency. Red light has a lower frequency than blue light. Because only one photon is needed to eject an electron and give it energy, an intense but low-frequency red light has no success in ejecting electrons, because each photon has to act alone. This is discussed on pages 585-587.
Update this answer!

You can help us out by revising, improving and updating this answer.

Update this answer

After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.