The periodic table, also called the periodic table of elements, is an organized arrangement of the 118 known chemical elements. The chemical elements are arranged from left to right and top to bottom ...

Discover the history, structure, and importance of the periodic table of elements, from Mendeleev’s discovery to modern scientific applications. When you purchase through links on our site, we may ...

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 ...