Carbon-12 is an isotope of carbon.

State what is meant by the term isotope.

How many protons and neutrons are in a nucleus of  $6{12}C$?

State the name of the interaction responsible for the repulsion between protons in the nucleus.

Describe the interaction that is responsible for keeping protons and neutrons together in a stable nucleus.

You should include details of the properties of the interaction in your answer.

Calculate the specific charge of the carbon-12 nucleus.

The equation below shows an incomplete equation for beta-minus decay.

State the name of particle X.

State the quark composition of the particle labelled X.

Charge is conserved during beta-minus decay. 

State two other properties which are conserved during beta-minus decay.

Complete the diagram below to show beta-minus decay.

This question is about the decay of the pion.

Determine if the interaction above is possible.

Electrons are fundamental particles. 

Explain what is meant by the term fundamental.

State the quark composition of the $\pi$⁺ meson.

Describe the difference between baryons and mesons.

Kaons are produced through the strong interaction. The equation below shows the production of a K⁺ meson.

Charge is conserved in this interactions. 

State two other properties that are conserved in this interaction.

The K⁰ meson has a strangeness of 1. 

Deduce the quark composition of the $\Lambda$⁰ particle.

The K⁰ decays to produce two pions. 

Write a decay equation for this interaction.

State and explain which interaction is responsible for the decay of the K⁰ meson.

Some particles and antiparticles can be classified as hadrons. 

Discuss the nature of hadrons. 

Your answer should include:

• the two classes of hadrons
• properties of hadrons
• the structure of a hadron in each class
• discussion of the stability of hadrons

Particle physicists complete experiments to identify the fundamental building blocks of matter.

State what is meant by an antiparticle.

Complete the table to show the antiparticles of each particle.

Describe what happens when a proton interacts with an antiproton.

Calculate the frequency of the photons emitted when a stationary proton undergoes annihilation. 

A positron is emitted when a nucleus undergoes $\beta$ ⁺ decay.

Write an equation to show $\beta$⁺ decay.

State which interaction is responsible for $\beta$⁺ decay.

Explain why the neutrino is emitted in this decay rather than an antineutrino.

Complete the diagram below to show $\beta$⁺ decay at the quark level.

This question is about particles and antiparticles. 

Describe the process of pair production.

A photon of frequency 2.52 x 10²⁰ Hz produces an electron and positron through pair production. 

Calculate the energy of the photon.

Calculate the kinetic energy of the electron produced.

The $\Sigma0$ baryon is produced through the strong interaction between a π⁺ meson and a neutron. 

Deduce the lepton number and baryon number of particle X

State the quark composition of particle X.

The equation below shows the decay of the $\Sigma+$ baryon.

State which interaction is responsible for this decay.

State the property that is not conserved in the decay of the $\Sigma+$ baryon.