Question

A metal foil has a threshold frequency of 5.45× 1014 Hz. Which of the colors of visible light have enough energy to eject electrons from this metal.

Answer 1

Convert 5.45E14 Hz to wavelength in meters and convert to energy required.
c = freq x wavelength
Then convert the low end and the high end colors (4000 Angstroms low end and 7000 Angstroms high end) to energy and compare.

Answer 2

yellow

Answer 3

green