Question 1
Paper 2Easy7 marksA sealed radioactive sample contains undecayed nuclei at time Figure 1 shows how changes with time.
(a)[2]
Use Figure 1 to state the number of undecayed nuclei at and at
(b)[2]
Using your values from (a) and the radioactive decay law determine the decay constant Give its unit.
(c)[3]
Determine the number of undecayed nuclei in the sample at Use the decay law and your value of from (b).