Everything we can see and touch, and quite a lot that we can’t as well, is made of tiny particles called atoms. Some substances, like particles of this iron, contain only one kind of atom. Iron is an ...

Chemical reactions occur when elements or compounds combine and create new compounds. Elements are substances that contain only one type of atom and are represented by unique symbols on the periodic ...

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 ...

This graphic was updated on April 12, 2019, to make clear that the element phosphorus does not appear in the 20 amino acids in the human body, at least initially. These amino acids can, however, be ...

Want to learn more about this centerpiece of chemistry? Take your pick from this collection of links about elements and the periodic table! Build an element ball, solve periodic puzzles, and check out ...

Discover the history, structure, and importance of the periodic table of elements, from Mendeleev’s discovery to modern scientific applications. When you purchase through links on our site, we may ...

One hundred fifty years after Russian chemist Dmitri Mendeleev published his system for neatly arranging the elements, the periodic table it gave birth to hangs in every chemistry classroom in the ...

There are lots of different substances but only just over a hundred elements. An element is a substance that is made up of only one kind of atom. The atoms in a particular element are the same as each ...