Asubstance that increases the rate of a chemical reaction without itself undergoing any permanent chemical change, change that into an idiom

Convert .347 kilometers to miles show your work

At element makes up all organic compounds?

Which of these describes how heat is transferred by convection* a. sunlight travels through space without the aid of fluids or solids. b. warm air rises and takes the heat with it, eventually, it cools and sinks c. air at the equator rises and sinks at the poles. d. air molecules touch the warm ground, heating them up *not conduction