Table 10.1 contains details of the nature and some properties of alpha, beta and gamma emissions. [Table 10.1]

1. (a)Complete Table 10.1 by filling in the missing details. [Table 10.1][6]
2. (b)(i)Surgical instruments in sealed plastic bags are placed in thin plastic boxes. A conveyor belt takes the boxes close to a cobalt-60 source which sterilises the instruments. This is shown in Fig. 10.1. [Figure 10.1] The cobalt-60 source is a radioactive isotope of cobalt that emits gamma-radiation. Describe what is meant by the term isotope.[2]
3. (b)(ii)Suggest a property of gamma-radiation that enables it to sterilise the instruments in the bags in the boxes.[1]
4. (b)(iii)State why a source emitting only alpha-radiation cannot be used in this way.[1]
5. (b)(iv)The half-life of cobalt-60 is 5.3 years. Explain why a source with a half-life of 5.3 minutes is unsuitable for use in this application.[1]
6. (c)(i)Geiger and Marsden performed an experiment in which alpha-particles were fired at a thin film of gold. Fig. 10.2 shows an alpha-particle passing close to the nucleus of a gold atom. [Figure 10.2] Explain why the alpha-particle is deflected.[2]
7. (c)(ii)In the experiment, most of the alpha-particles pass straight through the foil without deflection. Explain, using ideas about the structure of the atom, why this happens.[2]

This question uses a diagram from the original paper, which isn't shown here. Open the full paper from the past papers archive to see it.