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 ...

You are entirely forgiven for not knowing this, since they are not especially rare — cerium is about as common as copper. The problem is that they’re difficult to isolate and purify; it wouldn’t be ...