What are the properties of the following material which make the suitable for the use given: 1. glass in windows 2. wooden or plastic handles on a saucepan. 3. metals used for making airplanes

Glass:
transparent, so that we can see through the window

Wooden/plastic handles:
Heat insulator, so that our hands won't get burned if we lift up a hot sauce pan.

Metals for making airplanes:
Low density, so that less fuel is needed

These are just some physical properties, there may be more but these are the most common ones that are specially for the use given.

The density would be 1.622