A chemist mixed two substances together: a blue powder with no smell and a colorless liquid with a strong smell. Their repeating groups of atoms are shown above on the left. After they were mixed, the chemist analyzed the results and found two substances. One ending substance had the repeating group of atoms shown above on the right. Is the ending substance the same substance as the blue powder?

? you expect us to answer this? ? this is your schoolwork, i don't think we can with this, i think it would considering being

it is the minimum amount of material needed to sustain a fission reaction.

critical mass is the minimum amount of fissionable material that must be assembled for a sustained fission reaction to take place. although two to three neutrons are produced for every fission, not all of these neutrons are available for continuing the fission reaction. if the conditions are such that the neutrons are lost at a faster rate than they are formed by fission, the chain reaction will not be self-sustaining.   at the point where the chain reaction can become self-sustaining, this is referred to as critical mass.