Ductility
Ductility can be quantified by the fracture strain formula_1, which is the engineering strain at which a test specimen fractures during a uniaxial tensile test. Another commonly used measure is the reduction of area at fracture formula_2. The ductility of steel varies depending on the alloying constituents. Increasing the levels of carbon decreases ductility. Many plastics and amorphous solids, such as Play-Doh, are also malleable.
The most ductile metal is platinum and the most malleable metal is gold.
Caesium perchlorate
CsClO is the least soluble of the alkali metal perchlorates (followed by Rb, K, Li, and Na), a property which may be used for separatory purposes and even for gravimetric analysis. This low solubility played an important role in the characterization of francium as an alkali metal, as francium perchlorate coprecipitates with caesium perchlorate.