The periodic table, also called the periodic table of elements, is an organized arrangement of the 118 known chemical elements. The chemical elements are arranged from left to right and top to bottom ...

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. And here ...

These rules help in identifying and writing chemical symbols consistently across all elements. The symbol serves as a shorthand notation for each element's name in formulas and equations, making ...

This story was updated April 4 at 12:24 p.m. EDT. Hydrogen is the most common element in the universe, but why is that? To answer this question, "we need to go back to the Big Bang," said May Nyman, a ...