Note: This video is designed to help the teacher better understand the lesson and is NOT intended to be shown to students. It includes observations and conclusions that students are meant to make on ...

Why did they form at that time? Astronomers know from observing distant exploding stars that the size of the universe has ...

The “lead” of a pencil is actually made of a substance called graphite which is made of carbon atoms. The picture shows a close-up of one carbon atom. A hydrogen atom has one proton as the nucleus and ...

What’s actually going on inside protons and neutrons? What’s going on inside protons and neutrons? It’s a total mess - an infinite amount of quarks and antiquarks are constantly being created and ...