State what makes the gas cloud collapse.
Eventually nuclear fusion takes place in the star. State two conditions that must be present for nuclear fusion to occur in the star.
State the name and the number of each type of particle present in one nucleus of $^{235}_{92}\text{U}$.
State one feature that is identical in the nuclei of all uranium isotopes.
Describe how nuclear fission occurs in a nuclear reactor.
State one way in which nuclear fusion differs from nuclear fission.
Complete the nuclear equation that shows this decay: $^{235}_{92}\text{U} \rightarrow \,^{\,\,}_{\,}\text{Th} + \,^{\,}_{\,}\alpha$.
On Fig. 11.1, place the letter P at the position where the greatest number of flashes is seen on the screen.
Describe what can be seen on the other regions of the screen.
State two conclusions about gold atoms that were drawn from this experiment.