scientific reason for seeing through glass and not through a metallic foil?

There is a little bit more too it than "some things let light through". Here is what happens:

Atoms and molecules exist at "energy levels", where they store more energy than they normally would. There are ranges of energy levels that they can exist at, and radiation with energy corresponding to these ranges can be absorbed. These energies correspond roughly to that of visible light in a lot of chemicals.

In the case of glass, it only has weak absorption in the visible light range, so light can get through it. This is also true of air (which is also sufficiently non-dense to not significantly obstruct light). Something such as, say, plastic, does absorb in the visible range, so you cannot see through it. Water is an interesting example that's somewhere in between; in small amounts, you can see through it, but in large amounts, it does absorb enough light that you can't see through it.

In the case of metal, it's actually a little different- metal has lots of free electrons that float around in the metal. When light strikes the metal, the electrons absorb the light, and quickly re-emit it as light of the same energy (and hence same colour), which is why metals reflect light very well.

You see things When light bounces off of an object and into your eye, if there is a surface that is transparent like glass, the light can pass right through and go into your eye, If there is a reflective surface the light bounces off the back before it can get into you eye

some objects let light pass through and others dont i dont know what your expecting to get as an answer other then that