# Fundamental interaction & Nuclear physics
## State

| state | velocity | temperature |
|:------:|:--------:|:-----------:|
| solid | low | low |
| liquid | medium | medium |
| gas | high | high |

* Solid:
At low temperatures, matter is in a solid state. The molecular motion is low, with molecules mainly vibrating in fixed positions.

* Liquid:
As the temperature increases, matter enters a liquid state. The molecular motion is moderate, allowing molecules to move freely within a small range.

* Gas:
With further increase in temperature, matter becomes gaseous. The molecular motion is high, and molecules move freely throughout the entire container, with fast and widely distributed velocities.

## Energy and interaction within the atom
> 
> https://www.geeksforgeeks.org/what-is-an-atom/

**interaction**
* Strong interaction
Maintain stability within the nucleus
* Weak interaction
nuclear reaction

**energy**
Atomic mass $\simeq$ Nucleus mass $\simeq$ Nuclear energy
$$E = mc^2$$

## Nuclear reaction
> 
> https://www.ansto.gov.au/news/fission-vs-fusion-an-explainer

## Nuclear power plant
1. **Reactor**(nuclear energy)
1. **Steam**(thermal energy)
1. **Turbine**(kinetic energy)
1. **Electric generator**(Electric energy)


## Fundamental interaction

| Interaction | Mediators | Relative strength | Long-distance behavior (potential) | Range (m) |
|:---------------:|:--------------:|:-----------------:|:----------------------------------:|:------------:|
| Weak | W and Z bosons | $$10^{33}$$ | $${\frac {1}{r}}e^{-m_{(W,Z)}r}$$ | $$10^{-18}$$ |
| Strong | gluons | $$10^{38}$$ | $$\sim r$$ | $$10^{-15}$$ |
| Gravitation | gravitons | 1 | $$\frac{1}{r^2}$$ | $$\infty$$ |
| Electromagnetic | photons | $$10^{36}$$ | $$\frac{1}{r^{2.04}}$$ | $$\infty$$ |