Question 1
The following masses are known:
n | 1.008665 u |
H | 1.007825 u |
Ra | 226.025403 u |
What is the binding energy of

Ra? (1 u = 931.5 MeV/
c2)
◦ 2300 MeV
◦ 1900 MeV
◦ 2100 MeV
◦ 2500 MeV
◦ 1700 MeV
Question 2
The stability of

C with respect to alpha, beta-plus and beta-minus decay is to be determined. The following atomic masses are known:
He: | 4.002603 u |
Be: | 7.016928 u |
B: | 11.009305 u |
C: | 11.011433 u |
N: | 11.026742 u |
The

C nucleus is
◦ not subject to alpha, beta-plus or beta-minus decay.
◦ subject to beta-plus decay only.
◦ subject to beta-plus or beta-minus decay, but not to alpha decay.
◦ subject to alpha decay only.
◦ subject to beta-minus decay only.