Chemistry
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.
Teachers
A good teacher does not draw out; he gives out, and what he gives out is love. And by love I mean approval, or if you like, friendliness, good nature. The good teacher not only understands the child: he approves of the child.
A. S. Neill, The Problem Teacher (1939), p. 11.