Atoms

Atoms are the basic building blocks which all things are made of, they are so small that they can only be seen through a microscope.

### Further knowledge

Atoms of the same element that have different number of Neutrons are called Isotopes

## Structure Of An Atom

Atoms have 3 sub-atomic particles that make them:

* Proton

* Neutron

* Electrons

The Nucleus (middle of the Atom) is made out of Neutrons and Protons and around the atom, Electrons are located in shells that surround the Necueus, further are explained below:

* Neutrons
* Protons
* Electrons

## Neutron

### Mass Value

1

A particle with a **neutral charge**, it is located in the Nucleus along with Protons and has a **mass value of 1**

## Proton

### Mass Value

1

A particle with a **positive charge**, It is located in the Nucleus of the Atom, the amount of Protons there are in one element is called the Atomic Number for example Hydrogen which has the Atomic Number of 1 shows it has 1 Proton only

Protons have a **mass value of 1**

## Electron

### Mass Value

0.1800

A particle with a **negative charge**, it is located outside the Nucleus outside in Energy layers also referred to "Shells" which the Electrons can be arranged in , the last shell is called the **Valence Shell** and the Electrons in it are called the **Valance Electrons**, these electrons can be traded away to other atoms to make a stable atom (an atom with a full set of Valence Electrons in a Valence Shell).

* Atoms with a full set of Valence Electrons in the Valence shell is stable Atom

* Atoms that have gained one extra electron or lost an extra electron are unstable and need to gain one electron if it has lost an electron or lose one if it has gained one extra electron

The Shells each have a max amount of electrons that they hold:

1st Shell - 2 Electrons

2nd Shell - 8 Electrons

3rd Shell - 8 Electrons (can hold up to 18 counting electrons in sub shells but generally holds 8 most of time)

### Electron Configuration

The Electron Configuration is a diagram of how the Electrons are arranged

example of an Electron Configurations are below:

B
5

11

{\displaystyle B^{11}\_5}

2,3 - (this shows the number of electrons in each shell that add up to 5)

### Sub-Electron Shells

Sub Election Shells are shells within bigger shells, the number of the shell equals the number of sub-shells in a shell for example shell 2 has 2 sub-shells since the shell number is 2, shell 1 has 1 sub-shell since the shell number is 1

### Extras

The Electrons aren't considered in an elements Atomic Number as they are so small that they cant count towards the weight despite having a **mass value of 0.1800 (even tho it doesnt account for mass, it still has a tiny amount of mass)**

* 1837 Electrons equal 1 Proton
* When an atom loses or gains an Electron, it becomes something called an Ion

## Atoms And Their Mass

* The Total number of Protons and Neutrons in an Atom is called the Mass Number

* The mass of an atom depends on the number of Protons and Electrons in the Nucleus

* Because neutral Atoms have no charge, **the number of electrons equal the number of protons** therefore, the atomic number (total number of Protons) also tells us the number of Electrons in an Atom

## Important Words

* Neutrons
* Electrons
* Ions
* Charges
* Atomic Mass