# Physics - Beta Decay

> Source: https://ollybritton.com/notes/a-level/physics/topics/beta-decay/ · Updated: 2022-02-07 · Tags: physics, a-level, school, year-1

## Flashcards
### 2022-02-07
##### What are the two types of beta decay??
* Beta minus
* Beta plus

##### How should you write an electron in a beta decay equation??
$$
_{-1}^0 e
$$

##### 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??
1. The charge
2. The nucleon number

##### What does the beta decay equation look like for beta-minus decay??
$$
^1_0 n \to ^1_1 p + ^0_{-1} e + ^0_0 \bar{v}_e
$$

##### 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??
$$
d \to u + ^0_{-1}e + ^0_0 \bar{v}_e
$$

##### What force causes beta decay??
The weak nuclear force.

##### In beta-minus decay, is an electron or a positron emitted??
An electron.

##### In beta-plus decay, is an electron or a positron emitted??
A positron.

##### What does the beta decay equation look like for beta-plus decay??
$$
_1^1p \to _1^0 n + ^0_{+1}e + ^0_0 v_e
$$

##### What does the quark transformation equation look like for beta-plus decay??
$$
u \to d + ^0_{+1}e + ^0_0 v_e
$$

##### What happens in terms of quarks for beta-plus decay??
A up quark decays into a plus 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.

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