I know very little about the differences in types of bikes so I've come to the experts.

Can I find a mtb that weighs about the same as my Trek 7.6 FX hybrid? ~20 pounds?

Is it the suspension system that makes them weigh more, that is, if they do?

Can I use a mtb for my bad/cold weather commuter bike and will it give me more road stability in bad conditions compared to my hybrid with 700X32 tires?

Thanks for your input.