sentence: Atoms are very small, but the exact size changes depending on the element.
sentences_before: An 'atom' is the basic unit that makes up all matter. There are many different types of atoms, each with its own name, mass and size. These different types of atoms are called chemical elements. The chemical elements are organized on the periodic table. Examples of elements are hydrogen and gold.
sentences_after: Atoms range from 0.1 to 0.5 nanometers in width. One nanometer is around 100,000 times smaller than the width of a human hair. This makes atoms impossible to see without special tools. Equations must be used to see the way they work and how they interact with other atoms.
concept_name: atom
headings: Atom
categories: Chemistry Nuclear physics