Physics - Beta Decay
OCR A-Level Physics 2022
Flashcards
Types of beta decay
Beta-decay notation
How should you write an electron in a beta decay equation?
When denoting particles in a beta decay equation, such as $ _ y^x \alpha$, what does $y$ represent?
The charge.
When denoting particles in a beta decay equation, such as $ _ y^x \alpha$, what does $x$ represent?
The nucleon number.
What two quantities are conserved in a beta decay equation?
- The charge
- The nucleon number
Beta-minus decay
What does the beta decay equation look like for beta-minus decay?
Can you describe beta-minus decay in words?
A neutron decays into a proton and emits an electron.
What is true about the beta-minus particle (the electron) in a beta-decay equation that caused a problem historically?
It was emitted with a range of energies.
Why is a neutrino needed in a beta-decay equation?
Because otherwise energy is not fully conserved.
What is true about the “anti-ness” of the electron and the neutrino in beta decay?
They are opposite types, e.g. if an electron is emitted then an antielectron neutrino will be emitted.
What happens in terms of quarks for beta-minus decay?
A down quark decays into an up quark.
What does the quark transformation equation look like for beta-minus decay?
The force and emitted particle
Beta-plus decay
What does the beta decay equation look like for beta-plus decay?
What does the quark transformation equation look like for beta-plus decay?
What happens in terms of quarks for beta-plus decay?
A up quark decays into a down quark.
How can you remember which type of electron is emitted in beta-minus and beta-plus decay?
It’s like the minus or plus corresponds to $+1e$ or $-1e$ on the electron.