Exam-style multiple choice and written questions with full markschemes. Check multiple choice answers straight away, or type, photograph or draw a written answer and get it marked.
A sealed radioactive sample contains undecayed nuclei at time Figure 1 shows how changes with time.
Use Figure 1 to state the number of undecayed nuclei at and at
Using your values from (a) and the radioactive decay law determine the decay constant Give its unit.
Determine the number of undecayed nuclei in the sample at Use the decay law and your value of from (b).
A hypothetical nuclear reaction combines nuclei with nucleon numbers 12 and 24 to form a nucleus with nucleon number 36. The combined initial rest mass is Use
Here, is the mass equivalent of the increase in total binding energy. What is
Answer: B. The graph gives binding energy per nucleon, so multiply each value by its nucleon number to obtain total binding energy. The initial total is and the final total is Thus the increase is and
A: subtracts the per-nucleon values without weighting them by nucleon number, giving a negative result.
C: uses the initial total binding energy rather than its increase.
D: converts the energy increase to a mass in u but does not divide by the initial mass.
Remember: total binding energy is nucleon number multiplied by binding energy per nucleon.
Unlock every question in this topic, then type, photograph or draw your answer and have it marked against the markscheme. Find out where you are dropping marks.