Chemistry
The Periodic Table, Element by Element
The periodic table arranges all 118 known elements in order of atomic number, which is the number of protons in an atom. Rows are called periods and columns are called groups. Elements in the same group behave in similar ways.
Use Explore to learn about each element, then use Fill the table to place elements in the right cell from memory. Swipe sideways to see the whole table on a phone.
Atomic masses are rounded. For elements with no stable form (technetium, promethium and polonium onward), the mass number of the most stable known isotope is shown.