118 Elements and Their Symbols and Atomic Numbers: The periodic table is a well-organized chart that contains all the known elements in the universe. These elements are building blocks of matter ...

The formula H₂O shows that water is made from two atoms of hydrogen (H) bonded to one atom of oxygen (O). Katie: Time for some science. And today it's a chemistry classic, the periodic table.

The periodic table of chemical elements, often called the periodic table, organizes all discovered chemical elements in rows (called periods) and columns (called groups) according to increasing atomic ...