Cambridge IGCSE Chemistry · Syllabus 0620 · Stoichiometry
Chemical equation
What is Chemical equation?
A chemical equation represents a reaction using formulae, with the same number of atoms of each element on both sides; the coefficients written in front of each formula give the ratio in which the substances react, and state symbols show the physical state of each species under the reaction conditions.
This definition is part of the Stoichiometry chapter in Cambridge IGCSE Chemistry.