Table 7.1 shows the composition of four neutral atoms and one atom that has been ionised. These five particles are labelled P, Q, R, S and T. [Table 7.1]

1. (a)(i)The charge on an electron is -1.6 × 10⁻¹⁹C. State which of P, Q, R, S and T is the ionised atom.[1]
2. (a)(ii)State the size and the sign of the charge on the ionised atom.[1]
3. (b)State which pair from P, Q, R, S and T are isotopes of the same element.[1]
4. (c)(i)One of the atoms is a radioactive isotope that decays to produce one of the other atoms. Deduce which atom decays in this way.[1]
5. (c)(ii)Deduce which atom is the product of this decay.[1]
6. (c)(iii)Deduce which type of radioactive decay occurs.[1]
7. (c)(iv)The half-life for this radioactive decay is 33 years. A radioactive sample contains a large number of the atoms that decay in this way. Determine the fraction of this number of atoms that will decay in 99 years.[3]