When I first learned about the Rydberg formula, I was amazed that one expression could predict the wavelengths of so many spectral lines.

The chemist compared several Kekulé formulae to determine the most stable resonance structure.

The chemist compared several Kekulé formulas to determine the most accurate resonance depiction of the molecule.

The mathematician published several prime formulas that simplified the proofs.

In first-order logic, atomic formulas serve as the basic building blocks from which more complex formulas are constructed.

To validate the model we computed several closed formulae for the correlation functions and compared them with numerical simulations.

The textbook's appendix lists chemical formulas for common compounds alongside their molar masses.

Under the microscope, the students compared several chemical formulae drawn on the board to check for consistency.

The chemist counted the formula units in the crystal lattice to determine the compound's stoichiometry.

I stocked up on baby formulae, bottles, and pacifiers before the baby arrived.