Before you submit an error, please consult our Video Help page. Science Trek is available to stream on pbs.org and the free PBS App, available on iPhone, Apple TV, Android TV, Android smartphones, ...

Atomic Number and Mass Number of Elements: Atoms are the building blocks of matter. They are responsible for the format of all living and non-living things. Understanding their molecular structure and ...

The terms theory and model are defined, and students learn how a theory remains valid. Atomic Theory: The Development of the Atomic Theory: The terms theory and model are defined, and students learn ...

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 ...

If you've learned all the elements from actinium to zirconium, it's time to head back to the periodic table, where there's a new, extremely heavy element in town. In case you forgot your high school ...

At the far end of the periodic table is a realm where nothing is quite as it should be. The elements here, starting at atomic number 104 (rutherfordium), have never been found in nature. In fact, they ...

Creating mnemonic phrases can help you remember the order of elements, especially for the first 20 elements or specific groups. These phrases are general and are available on other free online sources ...

University of Nottingham’s chemistry professor Martyn Poliakoff says that most chemists don’t know the atomic number of most elements and that it’s a pain to look in the periodic table. That’s why ...