State one similarity and one difference between the nuclei of two different radon isotopes.
Radon-222 undergoes alpha-particle emission and becomes an isotope of polonium (Po). The proton number (atomic number) of polonium is 84. Find the number of neutrons in one atom of the polonium isotope.
Determine how many protons are in one atom of radon-222.
Describe how a neutral helium atom ($^{4}_{2}\text{He}$) is different from an alpha-particle.
Use Fig. 10.2 to find how many alpha-particles are produced in $7.6\,\text{days}$.
At the start, the inner glass tube contains $2.8 \times 10^{10}$ atoms of radon-222. Each radon-222 atom that decays gives an alpha-particle. Calculate how many radon-222 atoms are left after $7.6\,\text{days}$.
Using the number of radon-222 atoms present at the start and the number present after $7.6\,\text{days}$, calculate the half-life of radon-222.
The alpha-particles change into helium atoms, which are gathered in the vacuum shown in Fig. 10.1. Explain, in terms of the properties of alpha-particles, why the wall of the inner glass tube has to be extremely thin.
In some parts of the world, radon-222 builds up in the air inside buildings and is inhaled by people. Explain why having an alpha-emitter in the lungs is especially dangerous.