About 4. 6 billion years ago, the Solar System formed from a cloud of dust and gas collapsing in on itself due to gravity.

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 ...

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 ...

Sunscreen is a $10 billion business, with a seemingly endless array of products available for sale. Walk into your local drugstore and you’ll find chemical and mineral formulas in virtually every SPF ...