Is hair mousse a solied liqued or a gas and why ?

It is a liquid that has a gas mixed with it to create the foam. If you shake the can you can hear and feel the contents inside. Think of it in terms of whipped cream it's a liquid until you shake the can combining the aerosol gas with the liquid inside.

Hair mousse is like hair jel. its not something younwould expect it to be. it's somewhere around a liquid, but also a gas. it has both brands in a mixture to create somthing very hard to make and it holds hair in a perfect position to pose and stick. so the answer is probably liquid or gas. you're welcome.