A stationary polonium-210 nucleus (84210Po^{210}_{84}\text{Po}84210Po) decays into a nucleus of lead-206 by emitting an alpha-particle. The chemical symbol for lead is extPb ext{Pb}extPb. Write a nuclear equation for this decay.
The mass of the polonium-210 nucleus is 3.49×10−25 kg3.49 \times 10^{-25} \text{ kg}3.49×10−25 kg. After the decay, the lead-206 nucleus has a recoil speed of 3.1×105 m s−13.1 \times 10^5 \text{ m s}^{-1}3.1×105 m s−1. Calculate the kinetic energy, in MeV\text{MeV}MeV, of the emitted alpha-particle.
The uranium-235 (92235U^{235}_{92}\text{U}92235U) nucleus starts a decay chain which ends with a stable nucleus of lead-207 (82207Pb^{207}_{82}\text{Pb}82207Pb). Show that 11 particles are emitted during this decay chain. Explain your reasoning.
