Simple Definition of critical mass
: an amount of material (such as plutonium) that is large enough to allow a nuclear reaction to occur
: the size, number, or amount of something that is needed to cause a particular result
Full Definition of critical mass
: a size, number, or amount large enough to produce a particular result <the critical mass of activity needed for a retail store>
First Known Use of critical mass
Learn More about critical mass
Britannica.com: Encyclopedia article about "critical mass"
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