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 ...

A pure substance made from more than one type of element chemically bonded together. Elements bond in fixed ratios and so can be represented by a chemical formula. For example, sodium chloride has the ...

What is Atom and Molecule? Atoms and molecules are an important part of science and the building blocks of matter. Understanding them is the foundation for understanding all branches of science.