the following sets of quantum numbers, listed in the order n, l, ml, and ms, were written for the last electrons added to an atom. identify which sets are valid and classify the others by the rule or principle that is violated.

- lead + phosphoric acid = hydrogen + lead(ii) phosphate

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.