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 ...

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When it comes to science, chemistry is elemental. That pun is based on the fact that the main building blocks in the branch ...

THE “periodic” classification of the elements plays such an important part in courses of inorganic chemistry for students that a large wall diagram illustrating this classification has now become a ...

To the three requirements of a modern Periodic Table, as stated by A. A. Clifford 1, must be added a fourth, namely, that it should be in as close accord as possible with chemical facts, and above all ...

A century and a half ago, a Russian chemistry professor published a classification of all the known elements, organized by atomic weight. Today, the system that he created for his students — plus some ...