Blue light (l = 460 nm) is incident on a piece of potassium (W = ...

[Yi-Chen]

Blue light (l = 460 nm) is incident on a piece of potassium (W = 2.45 eV). What is the maximum kinetic energy of the ejected photoelectrons? (h = 6.63  10-34 Js, c = 3.00  108 m/s, 1 eV = 1.60  10-19 J, and 1 nm = 10-9 m)
 a. 1.0 eV
  c. 0.50 eV
  b. 0.25 eV
  d. 4.9 eV

Question 2

What is the energy of a photon whose frequency is 7.9  1020 Hz? (h = 6.63  10-34 Js and 1 eV = 1.60  10-19 J)
 a. 5.0 MeV
  c. 1.6 MeV
  b. 3.3 MeV
  d. 2.5 MeV

[sarahccccc]

Answer to Question 1

B

Answer to Question 2

B

[Yi-Chen]

Thank you!

[sarahccccc]

Always glad to help...