In an isolated system, two copper bars at different temperatures transfer energy until both are at the same temperature. how would the
transfer of energy be different if the bars were in an open system?
a. energy transfer would occur only between the copper bars.
b. energy transfer would occur between the copper bars and the surroundings.
c. no energy transfer would occur between the copper bars or the surroundings.
d. energy transfer would occur only with the surroundings.

може ли да зареждате повече информация, моля

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.