Which of the following measures the radiation given off by atoms per second?

curie
roentgen
gamma
becquerel

curie, one basic unit are used for measuring radiation. One is the curie, named after Marie and Pierre Curie. 

Aphysical change is one that you can put in and remove like a ham sandwich. the stuff you put in there can be changem its not permanet. a chemical change is on that can't be change thats permanet. like when you make a cake and bake it. you can't get those ingredients back.

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