A nucleus X is radioactive and decays into a nucleus Y.

X and Y are isotopes of the same element. Which combination of particles could have been emitted during the decay process?

A positively charged meson consists of a quark and an antiquark. What could be the quark and antiquark?

The figure shows part of a chart of nuclides where neutron number is plotted against proton

number. An unstable nuclide X decays by emitting an α-particle. Which nuclide is formed by the decay of nuclide X?

The nuclei of common isotopes of hydrogen, helium, lithium and beryllium are shown. Which nucleus contains equal numbers of up and down quarks?