Radix (chemia)
Radix in chemia organica est atomi vinculo covalentiae junxus est, qua unitas invariabilis in diversis substantiarum format.

Radix libera 
Radix libera est radix, non alio junxo, electrones impar habet.

Bibliographia
March, Jerry. 1985. Advanced Organic Chemistry: Reactions, Mechanisms, and Structure. Ed. 3a. Novi Eboraci: Wiley. ISBN 0471854727.
Brown, Theodore. 2002. Chemistry: the central science. Upper Saddle River Novae Caesareae: Prentice Hall. ISBN 0130669970.

Chemia