Adenosine triphosphate (ATP) is the energy currency of all living cells. It is the usable form of energy by cells for their life functions. Energy in ATP is harnessed via the hydrolysis of one of its phosphate molecules to form Adenosine diphosphate (ADP). The energy (measured in Kilojoules) needed by cells is released in this process.
In this case, a cell uses energy to pump hormones into the bloodstream. According to the question, 4 ATP's were used i.e. 4 ATP were converted to ADP. The hydrolysis of one ATP molecule releases 30.5 KJ/mol of energy needed for cellular work.
Hence, if 4 ATP were utilized by this particular cell, 4 × 30.5 KJ = 122 KJ of energy will be used by the cell to pump hormones.
the amount of neutrons in an atom can vary, which is why we have different types like uranium 242 and 243 etc. regarding how many neutrons it has, some hydrogen have no neutrons as well.