Why is air invisible?

Air – we can’t breathe without it, we can’t live without it, we know it’s made up of molecules, so why is it invisible? Chemist Vicky van der Geer-Bock will help us answer this question.If there’s a question whose answer feels invisible to you, we can help with that! Submit your Moment of Um question at BrainsOn.org/contact and we’ll help find the answer.