The critical mass of fissionable material is the largest mass necessary to sustain a nuclear fission chain reaction. single mass value that can sustain a nuclear fission chain reaction. mass at the critical point, which can sustain a nuclear fission chain reaction. smallest mass necessary to sustain a nuclear fission chain reaction.

smallest mass necessary to

Explanation:

The critical mass for a fissionable material is the smallest and the lowest quantity of a particular fissile material required to generate a self-sustaining fission chain reaction under specified conditions. The size's features are determined by a number of variables. Examples include;

The type of fissile material employed, its purity as well as concentration, the shape of the surrounding reaction system e.t.c.

"record the time to complete a chemical reaction" would most likely be part of a lab procedure.

definition

                    entropy is a measure of the randomness or the extent of disorder of a chemical process.

                      enthalpy is a measure of the heat change of a reaction occurring at a constant pressure.

measurement units:

                        entropy is measured in joule per kelvin (jk⁻¹)   whereas enthalpy is measured in joule per mole (jmol⁻¹)

requirements:

                            entropy has no requirements or limits, and its change is measured by the division between the heat change of the chemical process and the temperature.

                              in contrast, enthalpy can only be related to the heat change of the reaction under standard conditions.