---
## Structure of an atom
- All atoms have very small [[Nucleus]] made of [[Protons]] and [[Neutrons]] which is surrounded by [[Electrons]]. Atoms are also, mostly empty space since the nucleus is **so small** and the electrons are so far away from it *relatively*.
---
## Subatomic Particles
- [[Electrons]] **e-** have a **negative** electrical charge and are located **outside** the nucleus of an atom.
- Electrons and their configuration around an atom give an element many of its chemical properties
- [[Protons]] **p** have a **positive** electrical charge are located **inside** the nucleus of an atom contributing **one atomic mass unit**. They along with neutrons make up the mass of an atom.
- Second heaviest particle in an atom with the electron being significantly less.
- [[Neutrons]] **n** have a **neutral** electrical charge and contribute **one atomic mass unit** to an atom. They are located **inside** the nucleus of an atom.
- They are the **heaviest** particle in an atom.
---
## Atomic Notation
- Atomic number is the number of **protons**.
- Chemical elements that differ in the number of **Neutrons** are considered isotopes.
- Carbon-12 has 6 neutrons and 6 protons.
- Must have equal number of protons.
- An [[Ion]] is an element that has an uneven number of [[Protons]] and [[Electrons]]
- Protons - Electrons = charge
> [!quote]
> ##### Atomic notation
> ![[Atomic Notation.png]]
> ##### **An [[Ion]] can be denoted in the top right corner using + or - which will occur if there is a differing amount of [[Neutrons]] and [[Electrons]].**
---
## Atomic Mass
- Atomic mass describes the average weight of the most common isotopes of an element, taking in to consideration how abundant they are on earth.
>[!quote]
>##### Atomic mass equation
><br>
>
>![[Atomic structure atomic mass equation.png]]
---
## Other facts
The diameter of an atom is 10 to the fifth times larger then the nucleus.
- The nucleolus is positively charged.
- The angstrom (A) is a unit of atomic distance A = diameter of 1 atom.
---
## Bhor's model of the atom
- Bhor's model was new and unique at the time because he suggested that electrons orbit around the atom at specific *[[Orbitals]]* as seen in the image below. It ultimately was proved incorrect by the advent of [[Quantum mechanics]].
>[!quote]
>##### Bhor's model of the atom
><br>
>
>![[Pasted image 20230111131302.png | 400]]
---
## [[Quantum mechanics]]
- After Bhor's model a new model was needed to explain the distribution of electrons around the atom which is what [[Quantum mechanics]] allows us to do using an electron's **wave function**.
- For more information on this see [[Orbitals]].
---
#mainpage