Eli5: how do mirrors reflect back if they’re just made of glass and why are some materials reflective and others not?

Question

I’ve heard that mirrors have something behind them to make the glass reflective but how does that work?

In: Engineering

Answer 1

Traditional mirrors use a layer of silver applied to the glass. This produces a very shiny layer that reflects light extremely well.

Other materials can be polished to be reflective, some are just naturally reflective.