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 ...

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. WOMAN: The Greeks had many ideas about the chemistry of things. But the one who came closest to the ...

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 ...