Q:

Why does a transparent object create the rainbow effect(split the group of photons that creates white light)

Why do photons create the rainbow effect when they enter a crystal under the correct circumstances ?
it is not as if the photons are told to follow other photons with the same eV as them, then how are we able to split white light using transparent objects(under the correct circumstances)?

A:

This is refraction.  Photons of different wavelengths are bent differently. Each photon follows its own path. 
Monochromatic light isn't dispersed like that because there's only one wavelength, and they all bend the same amount. 
This also happens with radio waves, notably at a Gigahertz and higher, where plastics can act as lenses.

