The photoelectric effect

PH2.3 (a)- decribe how the photoelectric effect can be demonstrated

The photoelectric effect 

Shining light (or any electromagnetic radiation) on to a metal surface in order to release electrons is called the photoelectric effect. 

When you shine light into the metal surface, electrons from the metal surface are released. They move towards the collecting electrode and flow around the circuit, which gives a reading on the ammeter connected. 

So, is light a wave or it is a particle? 

We already know that waves with a larger amplitude carry more energy. For light, this means that a larger amplitude means a brighter light (because it is higher intensity), so surely, a brighter light will give iff more electrons...or will it?  

Think about ROYGBIV:

Shining a dim blue light onto the metal surface produces a small current on the ammeter that is connected to our circuit.  

Shining a bright blue light onto the metal surfaces produces a large current on the ammeter that is connected to our circuit. 

However... 

Shining a bright red light onto the metal surface produces zero current! 

The first two examples are what you might expect, brighter light= more energy current. BUT, the red light is just a bright as the blue one...get no…