The chemical formula of water is H2O.
ye
H2
HCl
NaHCO3
KOH
H2s2o8
AgNO3
It is butane.
Not every chemical formula requires subscript. For example table salt is NaCl, sodium chloride. No subscript. But most chemical formulae do require subscript, such as water, H2O.
chemical work using chemical formulae and chemical compounds
if it is a redox reaction sometimes you can add water to help balance the equation
A chemical equation is an expression in which symbols and formulae represent a chemical reaction. It shows the reactants on the left side and the products on the right side, with coefficients to balance the number of atoms on each side.