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.
Engineering is the creative application of science, mathematical methods, and empirical evidence to the innovation, design, construction, operation and maintenance of structures, machines, materials, devices, systems, processes, and organizations. The discipline of engineering encompasses a broad range of more specialized fields of engineering, each with a more specific emphasis on particular areas of applied mathematics, applied science, and types of application. See glossary of engineering.
There are two laws discrete,
Law for man, and law for thing;
The last builds town and fleet,
But it runs wild,
And doth the man unking.
Ralph Waldo Emerson, Ode, Inscribed to William H. Channing
Engineering is the art of directing the great sources of power in nature for the use and convenience of man.
Thomas Tredgold (1828), used in the Royal Charter of the Institution of Civil Engineers (ICE) published in: The Times, London, article CS102127326, 30 June 1828.