Chemistry is the scientific discipline involved with compounds composed of atoms, i.e. elements, and molecules, i.e. combinations of atoms: their composition, structure, properties, behavior and the changes they undergo during a reaction with other compounds. Chemistry addresses topics such as how atoms and molecules interact via chemical bonds to form new chemical compounds. There are four types of chemical bonds: covalent bonds, in which compounds share one or more electron(s); ionic bonds, in which a compound donates one or more electrons to another compound to produce ions (cations and anions); hydrogen bonds; and Van der Waals force bonds.
I recognize nothing that is not material. In physics, chemistry and biology I see only mechanics. The Universe is nothing but an infinite and complex mechanism. Its complexity is so great that it borders on randomness, giving the illusion of free will.
Konstantin Eduardovich Tsiolkovsky (1931) Monism of the Universe
Like literature, philosophy is not distinguished from other subjects by a specific approach to a subject-matter independent of it. Chemistry deals with chemicals, biology with life and astronomy with very large, very distant objects. Philosophy can boast no such definite subject-matter.
David Wood (philosopher) (1990) Philosophy At The Limit. p. 69