This year marks the 150th anniversary of the publication of Mendeleev’s Periodic Table of Chemical Elements in 1869. In celebration, the United Nations Educational, Scientific, and Cultural ...
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 ...
All matter–oceans, land, atmosphere, humans, animals, plants, food, materials, products, buildings–is made from 118 known chemical elements. These elements are ordered in the periodic table of ...
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