State the meaning of nuclear binding energy.
When uranium-235 ($^{235}_{92}\text{U}$) takes in a slow-moving neutron, one possible nuclear reaction is $$^{235}_{92}\text{U} + ^{1}_{0}\text{n} \rightarrow ^{95}_{42}\text{Mo} + ^{139}_{57}\text{La} + 2^{1}_{0}\text{n} + 7^{0}_{-1}\beta + \text{energy}.$$ State which type of nuclear reaction this is.
On Fig. 8.1, show the positions of: 1. the uranium-235 nucleus (label this point U), 2. the molybdenum-95 ($^{95}_{42}\text{Mo}$) nucleus (label this point Mo), 3. the lanthanum-139 ($^{139}_{57}\text{La}$) nucleus (label this point La).
Fig. 8.1 shows how the binding energy per nucleon $B_E$ changes with nucleon number $A$. When uranium-235 ($^{235}_{92}\text{U}$) takes in a slow-moving neutron, one possible nuclear reaction is $$^{235}_{92}\text{U} + ^{1}_{0}\text{n} \rightarrow ^{95}_{42}\text{Mo} + ^{139}_{57}\text{La} + 2^{1}_{0}\text{n} + 7^{0}_{-1}\beta + \text{energy}.$$
The masses of some particles and nuclei are shown in Fig. 8.2. For this reaction, calculate: 1. the change in rest mass, in $\text{u}$, 2. the energy released, in MeV, to three significant figures.