118 elements and seven periods, though just one period of high school chemistry is enough to get confused by it. This week, we’re exploring the history behind the periodic table.

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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 ...