From the brains behind brains on, this is the moment of um.

Answering those questions that make you go. Oh, um, and uh, and uh, and uh, and up, uh,

that, uh, that, uh, and up, uh, uh, and up, uh,

and stuff, uh, and stuff, uh, and stuff, uh,

and uh, and uh, Um, um, um, from,

and uh, I'm, uh, and uh,

uh, and uh, uh, uh,

uh, um...

Welcome to a moment of um from 8 p.m. studios. I'm Molly Bloom. Put your shoes on, open your front door, and take a big, big breath.

Oh, fresh air feels good right? Air is essential to everything we do.

Breathing, walking, running, living. If it's so important to our life force,

then why the heck can't we see it?

Hi, I'm Kalia, and I'm Anya.

We're from Orland Park, Illinois, and our question is,

Why is air invisible?

Hi, I'm Vicky Vandergare.

I studied chemistry and in my job I try to ensure that the medicines you buy at a pharmacy are safe to use.

To understand this, first you need to remember that all the matter around you is made up of molecules.

Some of these are big complicated molecules or collections of molecules. Some of these are big complicated molecules or collections of molecules, and some are really simple molecules.

In general, the big complicated molecules can do a lot of different things when light hits them.

They can absorb the light or they can scatter in all directions or even send a light

straight back like a ping-pong ball. For example, the molecules in carrots are really good at sending back orange bits of light and absorbing the rest, which is why carrots appear orange.

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