CCEA A-Level Physics 1210
Physical Quantities, Scalars and Vectors
Moments and Equilibrium
Linear Motion and Dynamics
Newton's Laws of Motion
Linear Momentum and Impulse
Work, Energy and Power
Current, Charge and Potential Difference
Resistance and Resistivity
Internal Resistance and Potential Dividers
Waves
Refraction
Lenses
Superposition, Interference and Diffraction
Quantum Physics
Wave-Particle Duality
Astronomy
Practical Skills and Data Analysis
Deformation of Solids
Thermal Physics
Uniform Circular Motion
Simple Harmonic Motion
The Nucleus and Radioactive Decay
Nuclear Energy, Fission and Fusion
Gravitational Fields
Electric Fields
Capacitors
Magnetic Fields
Charged Particles and Accelerators
Fundamental Particles
Beta decay in the quark model
- 3 things to know
- Unit A2 2
Overview
Beta-minus decay at the quark level and beta-plus decay at the quark level.
What you need to know
Answer each one before you reveal it.
Write the equation for beta-minus decay of a neutron.
Describe beta-minus decay at the quark level.
Questions from this subtopic
Each one with the model answer underneath.
- 1
Write the equation for beta-minus decay of a neutron.
Model answer
n → p + e⁻ + ν̄ₑ, a neutron becoming a proton with the emission of an electron and an electron antineutrino.
- 2
Describe beta-minus decay at the quark level.
Model answer
A down quark in the neutron changes into an up quark, emitting an electron and an electron antineutrino.
- 3
Write the quark equation for beta-minus decay.
Model answer
d → u + e⁻ + ν̄ₑ.
- 4
Show that the quark change turns a neutron into a proton.
Model answer
The neutron is udd, and changing one down quark to an up quark gives uud, which is the proton.
- 5
Which exchange particle mediates beta-minus decay?
Model answer
The W⁻ boson, emitted by the down quark as it becomes an up quark and then decaying into the electron and the antineutrino.
- 6
Write the equation for beta-plus decay.
Model answer
p → n + e⁺ + νₑ, a proton becoming a neutron with the emission of a positron and an electron neutrino.
Other ways to work this
The same content, four other ways.
What is inside Levo
Six ways to work the same material.
Every question in Fundamental Particles, on a schedule.
Attempt a question from memory, write the correct version, then attempt it again. Levo records the jump between your first attempt and your last, and brings each question back on the day you are due to forget it.
Or £46 a year, about £3.83 a month. Cancel anytime.