Practise Edexcel A-Level Physics nuclear decay through binding energy, fusion and fission, radiation properties, nuclear equations and radioactive half-life calculations.
A nucleus of polonium-210 decays to lead-206 by emitting an alpha particle. The masses of the particles are shown in the table.
Show that the energy released in the decay is about .
Actinium-225 is a radioactive isotope. It decays to francium by emitting alpha particles. Actinium-225 has a short half-life, which makes it suitable for medical applications.
Complete the nuclear equation for this decay.
In a radioactive decay, energy is released and the total mass decreases.
Show that the energy released if the mass decreases by 1 u is about 930 MeV .
The activity of a sample of actinium-225 is 7.4 × 10^7 Bq when it is prepared.
Calculate the number of actinium atoms in the sample 7.0 days later.
half-life of actinium-225 = 9.9 days
Number of actinium atoms after 7.0 days =
In France, scientists from many countries are working together to build the International Thermonuclear Experimental Reactor (ITER).
On the ITER website it states:
"Fusion is the energy source of the Sun and stars. In the core of these stellar bodies, hydrogen nuclei fuse into helium nuclei and release tremendous amounts of energy."
Explain why energy is released when hydrogen nuclei fuse to form helium nuclei.
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It is hoped that the ITER will be the first fusion device on Earth to maintain nuclear fusion for long periods of time.
To achieve fusion in the ITER, a hot plasma is used.
The plasma must
- be at an extremely high temperature
- have sufficient density for fusion.
Explain why each of these two conditions must be met.
The graph shows the variation of binding energy per nucleon with proton number Z.
In one possible fusion reaction, a nucleus of ²H fuses with a nucleus of ³H to form a nucleus of ⁴He and a neutron.
Calculate the energy released in this reaction.
