1. reaction velocity
Wikipedia definition
2. Reaction rateThe reaction rate (rate of reaction) or speed of reaction for a reactant or product in a particular reaction is intuitively defined as how fast or slow a reaction takes place. For example, the oxidation of iron under the atmosphere is a slow reaction that can take many years, but the combustion of butane in a fire is a reaction that takes place in fractions of a second. Chemical kinetics is the part of physical chemistry that studies reaction rates.
Read “Reaction rate” on English Wikipedia
Read “反応速度” on Japanese Wikipedia
Read “Reaction rate” on DBpedia


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