The news broke that a railroad car, loaded with pure sodium, had just derailed and was spilling its contents. A television reporter called me for an explanation of why firefighters were not allowed to ...

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 ...

Editor's note: The following is a text-only version. The complete version with artwork is available for purchase here (PDF). The periodic table of the elements is one of the most powerful icons in ...

Every field of science has its favorite anniversary. For physics, it’s Newton’s Principia of 1687, the book that introduced the laws of motion and gravity. Biology celebrates Darwin’s On the Origin of ...