How can you express the rate of a chemical reaction

Reaction rate, the speed at which a chemical reaction proceeds. It is often expressed in terms of either the concentration (amount per unit volume) of a product that is formed in a unit of time or the concentration of a reactant that is consumed in a unit of time.

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space exploration has led to the development and technological improvement of many everyday items. (if this answer is wrong i will find the right answer) : )

i just calculated it all out, and not including weekends, and all the different days off. as of this school year (2018-2019) students are spending 2198 hours in school this year