A chemical chemical is any substance that is a mixture of atoms, molecules, or other elements.
In the case of chlorine, a chemical is a combination of oxygen and chlorine atoms, while in the case in the digital notebook, it’s an electron configuration.
In fact, there’s no such thing as a chemical compound without a chemical nucleus, a unit of energy that is the basis for chemical bonds.
Here’s how to write a chemical chemical.
[H/T: Science Daily]