Name two ways you can tell if something is a chemical change

What happens in the particles of a gas when the gas is compressed

An engineer decides to use a slightly weaker material rather than a stronger material, since she knows that the stronger material can break suddenly. this is an example of what? a choosing a material that will show warning before it fails b using composite materials that combine strength c using a material for multiple applications d using design techniques that increase efficiency and reduce cost

Scuba divers use tanks of compressed air to them breathe. gases can be compressed because?