(a)[2]
Explain what is meant by hydrogen isotopes.
(b(i))[1]
Using Fig. 11.1, state how many neutrons are in the nucleus of the isotope $^{3}_{1}\text{H}$.
(b(ii))[1]
Using Fig. 11.1, state what particle A is called.
(b(iii))[1]
Using Fig. 11.1, state the proton number for particle B.
(b(iv))[1]
Using Fig. 11.1, state the nucleon number, or mass number, of particle B.
(c)[2]
A very high temperature is needed to push nuclei together. Explain why.
(d)[3]
A star is formed from a large cloud of gas and dust in space. Describe what happens during the star’s formation.
(e(i))[2]
The hydrogen isotope $^{3}_{1}\text{H}$ has a half-life of 12 years. State what half-life means.
(e(ii))[2]
A sample starts with 16 000 atoms of $^{3}_{1}\text{H}$. Calculate how many atoms of $^{3}_{1}\text{H}$ remain in the sample after 48 years.