Photons are incident on a metal surface.
Electrons are accelerated from rest through a potential difference V.
Photons are incident on a metal surface. Electrons are emitted from the surface. What single change may result in no electrons being emitted from the surface?
Doubling the wavelength of the photons
Halving the wavelength of the photons
Doubling the number of photons incident on the surface per second
Halving the number of photons incident on the surface per second