Answer:
The energy harnessed in nuclei is released in nuclear reactions. Fission is the splitting of a heavy nucleus into lighter nuclei and fusion is the combining of nuclei to form a bigger and heavier nucleus. The consequence of fission or fusion is the absorption or release of energy.
Introduction
Lanthanide belongs to period 6, and actinides belongs to period 7
% by mass = (mass solute/mass solution)*100%
mass of the solute = 54.7 g
mass of the solution = mass solute + mass solvent=54.7+500=554.7 g
% by mass = (54.7/554.7)*100%≈0.0986*100% = 9.86%