system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5:What makes something transparent?

ex.  What is it exactly that enables us to see through oxygen but not silver?
gpt
**Simple answer:**

The gaps between the atoms is large enough that lights can pass though. (This is the incorrect answer though, but easy enough to know)

**Headache answer:**

Many people thinks that the reason light shines through transparent materials is because the atoms are spread apart enough, but that is not true.  Even in very dense solid like lead, the spacing between atoms are still very large when compared to a light photon.
The reason you don't see a light shining through your solid silver plate is because the energy from the photon is absorbed.  The electrons in the silver plate gets excited to a higher energy level when light shines through it, and it will be able to absorb some light photons. Oxygen lets light pass through because their electrons in oxygen need more energy to get riled up. The light is able to pass through because the electron is not absorbing them.

**ELI5:**

Imagine light is a girl in bikini running through a crowd at extremely high speed.  If in front of her is another bunch of (straight) girls, the crowd moves apart letting the bikini girl run through to avoid a collision.  This is oxygen.

Silver is however a bunch of sex-crazed (straight) men.  They get very excited to see a bikini girl running towards them and will do all they can to stop the bikini girl in her tracks.

Substances that reflect light are a bunch of sex-crazed (gay) men.  They don't want the bikini girl to ruin their party so they will do all they do to stop bikini girl in her tracks and to push her away.