The periodic table has become an icon of science. Its rows and columns provide a tidy way of showcasing the elements — the ingredients that make up the universe. It seems obvious today, but it wasn’t ...

How is the table organized? The Periodic Table, first compiled by Russian chemist Dmitri Mendeleyev, is organized by the number of protons in the nucleus of each element's atom, known as the atomic ...

About the student asking the question: She is a sophomore at Corning-Painted Post. Leah wants to be a physical therapist. She enjoys swimming, music, drama, hiking, and visiting national parks.

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 ...