.The corpuscular theory by Einstein explains that light is a group of photons which behave like a wave .Photons carry a fixed amount of energy but no mass. The energy that the photon contains would depend on how long the wavelength . Increasing the intensity of the light would increase the electrons ejected. Einstein started to work on Planck's theory , he started by shining ultraviolet on a surface of metal. .When he did this , Einstein realised that the electrons were emitted by from the surface.Einstein explained that the tiny clumps full withe energy are photons . They act like billiards, transferring energy to electrons. Once the electrons , are freed they move along the metal .
Refraction
Refraction is when light waves change speed when passing boundaries with different densities, this causes them to change direction, this is called refraction. Refraction does not bend at 90'c and moves straight forward. For example when light passes through water it slows down.This will change the direction of light. Refraction depends on the angle of the incident ray and the change of speed . The speed slows down then where there is a higher refractive index such as air into glass.The light will bend more towards the normal line On the on the other hand if there is lower refractive index , it will speed up.The light will bend away from the normal line .Refraction can cause a spectrum for example sunlight shining through window, creating a spectrum of light on the oppisate side
Reflection
Reflection is when light bounces off the object. if the surface is smooth the light bounced off would reflect. The types of reflection is diffusion reflection which is light bouncing off in different directions off a rough surface , spectacular reflection which is the angle reflected off a reflecting surface called the angle of incidence for example a tree reflected off water.The angles of incidence and reflection are measured between the light ray and the normal .
SPECTRUM OF COLOURS
Light is made up of wavelengths of light and each wavelength is a different colours such as violet,indigo,blue.green,yellow,orange and red.These colors made up of the visual spectrum with wavelengths from dark red at 700nm and violet at 400nm. This is called the visible spectrum as our eyes can see it . The spectrum is ordered from the shortest to the longest wavelength .The full range of wave lengths is called the electromagnetic spectrum.