Learn with Mentor · 8 min
Chemical Formulae and Molecular Models
Read formulae, count atoms from subscripts, and compare formulae with 3D molecular models.
Let's start
Formulae are compact atom counts
A chemical formula is a compact way to show which elements are present and how many atoms of each element are in one molecule or formula unit. It uses standard element symbols, such as C for carbon, H for hydrogen, O for oxygen, Na for sodium and Cl for chlorine.