Light -- how light particles can penetrate through glass?

No it is not. Lead glass has a higher density than aluminium, but the former is transparent while the latter is not.

To be not transparent, there has to be something that can absorb (or scatter) light - usually electrons that can reach a higher energy level. The electrons in transparent glasses are bound to their atoms/molecules and do not have accessible energy levels they could go to from the absorption of light.

 

If the atoms making up the material have the right characteristics, then the light will be absorbed by the electrons in the material.