Template:Infobox atom

Atom
Helium atom ground state. A drawing of the helium atom, showing the nucleus (pink) and the electron cloud (black). The nucleus is made of two protons (red) and two neutrons (violet). The black bar is one angstrom (10−10 m or 0.1 nm).
Properties
Mass range	1.67×10−27 to 4.52×10−25 kg
Diameter range	62 pm (He) to 520 pm (Cs) (data page)
Components	Electrons and a compact nucleus of protons and neutrons