Core Atomic
Structure: Nature of light
Slide 10 of 24
The photoelectric
effect
This effect is similar to tossing stones at a
bucket of water.
Stones that are thrown with enough force will
cause water to splash out of the bucket.
–Similarly, photons
that strike certain metals with enough energy will cause electrons
to jump from the metal atoms.
Stones can also be
slipped carefully into a bucket without causing a splash.
–Similarly, low-energy
photons will strike metals without releasing electrons.
It is for similar
reasons that red light is used while working in a darkroom.
–Yellow light or a
regular (white light) bulb for example would not be safe at all.
–Using light that has
higher frequency than red would expose the photographic paper.