1) Which of the interactions is not possible? [1]
A: $\begin{array}{*{20}{c}}
4\\
2
\end{array}He + \begin{array}{*{20}{c}}
1\\
0
\end{array}n \to \begin{array}{*{20}{c}}
5\\
2
\end{array}He$
B: $\begin{array}{*{20}{c}}
{209}\\
{84}
\end{array}Po \to \begin{array}{*{20}{c}}
{205}\\
{82}
\end{array}Pb + \begin{array}{*{20}{c}}
4\\
2
\end{array}\alpha $
C: $\begin{array}{*{20}{c}}
{14}\\
8
\end{array}O \to \begin{array}{*{20}{c}}
{14}\\
7
\end{array}N + \begin{array}{*{20}{c}}
0\\
1
\end{array}\beta  + \begin{array}{*{20}{c}}
0\\
0
\end{array}V$
D: $\begin{array}{*{20}{c}}
{31}\\
{14}
\end{array}Si \to \begin{array}{*{20}{c}}
{31}\\
{15}
\end{array}N + \begin{array}{*{20}{c}}
0\\
1
\end{array}\beta  + \begin{array}{*{20}{c}}
0\\
0
\end{array}V$

2) Hadrons are made up from quarks.
Which combination of quarks could make up a meson? [1]
A: $dd\overline s $
B: ssc
C: $s\overline b $
D: sc

3) Explain why the most strongly ionising radiation ($\alpha  - $particles) is the least penetrating, while the least ionising ($\gamma  - $rays) is the most penetrating. [1]

4) Before Rutherford’s model, scientists believed that the atom was made up of negatively charged electrons embedded in a ‘plum pudding’ of positive charge that was spread throughout the atom. Explain how the $\alpha  - $particle scattering experiment proved that this old model of the atom was incorrect. [3]

5) A nucleus of strontium has a nucleon number of 90 and a proton number of 38.
Describe the structure of this strontium nucleus. [1]

6) State the changes that take place in a nucleus when it emits an $\alpha  - $particle and then two ${\beta ^ - } - $particles. [5]

7) The nuclide of iodine with a nucleon number of 131 and a proton number 53 emits a ${\beta ^ - } - $particle. Write a nuclear equation for this decay. [3]

8) An isotope of carbon $\begin{array}{*{20}{c}}
{14}\\
6
\end{array}C$ emits a ${\beta ^ - } - $particle and changes into an isotope of nitrogen (N).
a: What are ${\beta ^ - } - $particles? [1]
b: Write a nuclear decay equation for the decay. [2]
c: Draw a graph with the y-axis representing nucleon numbers between 10 and 16 and the x-axis representing proton numbers between 4 and 10. On your graph, mark:
i- the isotope $\begin{array}{*{20}{c}}
{14}\\
6
\end{array}C$ [2]
ii- the daughter nucleus produced in the decay. [1]
[Total: 6]

9) The uranium isotopes $U - 236$ and $U - 237$ both emit radioactive particles. A nucleus of uranium-237 may be written as $\begin{array}{*{20}{c}}
{237}\\
92
\end{array}U$ and emits a ${\beta ^ - } - $particle. A nucleus of uranium-236 emits an α-particle. The number of protons in a nucleus of uranium is 92.
a: Describe the differences between an $\alpha  - $particle and a ${\beta ^ - } - $particle. [4]
b: Explain how uranium can exist in a number of different isotopes. [2]
c: Write down the nuclear equation for the decay of U-236. [2]
[Total: 8]

10) Approximate values for the radius of a gold atom and the radius of a gold nucleus are ${10^{ - 10}}\,m$ and ${10^{ - 15}}\,m$, respectively.
a: Estimate the ratio of the volume of a gold atom to the volume of a gold nucleus. [2]
b: The density of gold is $19000\,\,kg\,{m^{ - 3}}$. Estimate the density of a gold nucleus, stating any assumptions that you make in your answer. [3]
[Total: 5]

11) The nuclide of lead $\begin{array}{*{20}{c}}
{210}\\
82
\end{array}Pb$ decays in three separate stages by $\alpha $ and ${\beta ^ - }$ emission to another lead nuclide, $\begin{array}{*{20}{c}}
{206}\\
82
\end{array}Pb$.
a: Describe the structure of a nucleus of $\begin{array}{*{20}{c}}
{206}\\
82
\end{array}Pb$. [2]
b: $\alpha  - $ and ${\beta ^ - } - $particles are known as ionising radiations. State and explain why such radiations can be described as ionising. [2]
c: The two lead nuclides are shown in the graph, which plots nucleon number A against proton number Z.
Copy the graph and, on your copy, draw three arrows to represent one possible route for the three decays between the two isotopes of lead. Label
each arrow to show whether an α-particle or a ${\beta ^ - } - $particle is emitted. [3]

[Total: 7]

12) Geiger and Marsden carried out an experiment to investigate the structure of the atom. In this experiment, $\alpha  - $particles were scattered by a thin film of gold.
a: When Rutherford analysed their results, what conclusions did he draw about the distribution of mass and charge in the atom? [2]
b: Describe and explain the experimental observations that led to these conclusions. [3]
[Total: 5]

13) Beta decay occurs as either ${\beta ^ + }$ decay or ${\beta ^ - }$ decay. An isotope of calcium Ca decays by ${\beta ^ + }$ emission into the isotope $\begin{array}{*{20}{c}}
{46}\\
{21}
\end{array}Sc$ , and an isotope of magnesium $\begin{array}{*{20}{c}}
{23}\\
{12}
\end{array}Mg$ decays by $\beta $ emission into the isotope $\begin{array}{*{20}{c}}
{23}\\
{11}
\end{array}Na$.
a: Copy and complete the following decay equations for the calcium and magnesium isotopes.
i- decay of calcium: $\begin{array}{*{20}{c}}
{46}\\
{20}
\end{array}Ca \to Sc + {\beta ^ + } + ...$ [1]
ii- decay of magnesium: $\begin{array}{*{20}{c}}
{23}\\
{12}
\end{array}Mg \to Na + {\beta ^ + } + ...$ [1]
b: State what happens in each type of β decay in terms of the quark model of nucleons.
i- ${\beta ^ - }$ decay [1]
ii- ${\beta ^ + }$ decay. [1]
c: Name the force responsible for $\beta $ decay. [1]
[Total: 5]

14) a: A quark is a fundamental particle but a neutron is not. Explain what this statement means. [1]
b: A proton and a neutron each contain three quarks, either up or down quarks.
i- Copy and complete the table to show the charge on a proton and a neutron and the quarks that they contain. [2]

ii- Using information from your table, suggest why some quarks must have a positive charge and some quarks a negative charge. [2]
c: State what interaction is responsible for holding the nucleus together. [1]
d: When a neutron decays it produces an electron and two other particles.
Copy and complete the decay equation for a neutron.
[2]
e: The electron and the neutron belong to different groups of particles.
Copy and complete the table to show the group of particles to which the electron and neutron belong and state the name of another member of each group. [2]

[Total: 10]