**Paper 1 H - SAMPLE SET 1 Q9**

9) A student models the random nature of radioactive decay using 100 dice.

He rolls the dice and removes any that land with the number 6 facing upwards.

He rolls the remaining dice again.

The student repeats this process a number of times.

He rolls the dice and removes any that land with the number 6 facing upwards.

He rolls the remaining dice again.

The student repeats this process a number of times.

**Table 1**shows his results.9.1) Give

1. ___________________________________

2. ___________________________________

The student’s results are shown in

**two**reasons why this is a good model for the random nature of radioactive decay. [2 marks]1. ___________________________________

2. ___________________________________

The student’s results are shown in

**Figure 11**.9.2) Use

Show on

**Figure 11**to determine the half-life for these dice using this model.Show on

**Figure 11**how you work out your answer. [2 marks]

Half-life = ____________ rolls

A teacher uses a protactinium (Pa) generator to produce a sample of radioactive material that has a half-life of 70 seconds.

In the first stage in the protactinium generator, uranium (U) decays into thorium (Th) and alpha (α) radiation is emitted.

The decay can be represented by the equation shown in

In the first stage in the protactinium generator, uranium (U) decays into thorium (Th) and alpha (α) radiation is emitted.

The decay can be represented by the equation shown in

**Figure 12**.9.3) Determine the atomic number of thorium (Th) 234. [1 mark]

Atomic number = ___________

When protactinium decays, a new element is formed and radiation is emitted.

The decay can be represented by the equation shown in

The decay can be represented by the equation shown in

**Figure 13**.9.4) When protactinium decays, a new element,

Use information from

9.5) Determine the type of radiation emitted as protactinium decays into a new element.

Give a reason for your answer. [2 marks]

9.6) The teacher wears polythene gloves as a safety precaution when handling radioactive materials.

The polythene gloves do

Explain why the teacher wears polythene gloves. [2 marks]

**X**, is formed.Use information from

**Figure 12**and**Figure 13**to determine the name of element**X**. [1 mark]9.5) Determine the type of radiation emitted as protactinium decays into a new element.

Give a reason for your answer. [2 marks]

9.6) The teacher wears polythene gloves as a safety precaution when handling radioactive materials.

The polythene gloves do

**not**stop the teacher’s hands from being irradiated.Explain why the teacher wears polythene gloves. [2 marks]

**(Total for Question 9 = 10 marks)**