27.18. R http://www.ck12.org
The use of two or more Lewis structures to represent the covalent bonding in a molecule.
reversible reaction
A reaction in which the conversion of reactants to products and the conversion of products to reactants occur
simultaneously.
roentgen
A unit that measures nuclear radiation and is equal to the amount of radiation that produces 2× 109 ion pairs
when it passes through 1 cm^3 of air.