What is density? what does it tell you about the substance?

The modern periodic table has groups.

The term gas is limited to those substances that exist in the gaseous state at

If you fill your car tire to a pressure of 32 psi (pounds per square inch) on a hot summer day when the temperature is 35°c (95°f), what is the pressure (in psi) on a cold winter day when the temperature is -15°c (5°f)? assume no gas leaks out between measurements and the volume of the tire does not change.