A 60co source is labeled 4. 00 mci, but its present activity is found to be 1. 85×107 bq. (a) what is the present activity in mci? (b) how long ago did it actually have a 4. 00-mci activity?.

Cis the

Hellosubatomic particles  are  particles  that are smaller than the atom. protons, neutrons, and electrons are the three mainsubatomic particles  found in an atom. protons have a positive (+)  charge. an easy way to remember this is to remember that both neutron and no  electrical charge  start with the letter "n."have a nice day

The answer is b on edgenuity