But the ancient Greeks certainly had numbers. In fact, they had what was in some ways a much more elegant system than the ...

Atoms can form strong bonds with each other, making molecules. Symbols and formulae Letters from the alphabet are used to represent chemical elements. An element’s chemical symbol is a single ...

Dr. Tim: So this is the periodic table and each letter on it represents a different element. We call these letters symbols. And an element is a pure substance made from only one type of atom.