Chemical Formula Posted on 5th November 201520th July 2021 by ThePD (The Project Definition) Chemical Formula is an expression about the chemical proportions of atoms which states the number and type of atoms in a molecule. Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window)Click to share on LinkedIn (Opens in new window) Related Posted in Science and tagged chemistry. ThePD (The Project Definition) ThePD has been developing the Preferred Project Definitions based on the actual project execution and operation experiences and knowledge with the Project Language, and sharing with you daily basis.