An -decay process is represented schematically as ^ 238 _ 92 U ; ; ^ 234 _ 90 Th + ^…

PHYSICS · Multi-part · A Level · Physics · Nuclear physics · Nuclear physics

Problem

\alpha

-decay process is represented schematically as

^{238}_{\ 92}\text{U} \;\rightarrow\; ^{234}_{\ 90}\text{Th} + ^{4}_{\ 2}\text{He}.

The following nuclear masses are given:

^{238}_{\ 92}\text{U}: 238.050788\,\text{u}

^{234}_{\ 90}\text{Th}: 234.043593\,\text{u}

^{4}_{\ 2}\text{He}: 4.002603\,\text{u}

. (Atomic-electron masses are already included in these tabulated values.) (a) Write the numerical value of the total mass of the decay products and hence find the mass defect

\Delta M

for the decay. (b) Calculate the energy (in MeV) released in this

\alpha

-decay. Use

1\,\text{u}=931\,\text{MeV}

. (c) Briefly state how this released energy is shared between the emitted

\alpha

-particle and the recoiling thorium nucleus.

Related theory

Mass-Energy Equivalence
Nuclear Binding Energy
Mass defect and binding energy
Nuclear physics
Nuclei

Browse the problem library