Electron arrangement
Electron shells
Electron shells naturally want to have a full outer shell
Level of shell |
Number of electrons |
1st level |
2 |
2nd level |
8 |
3rd level |
8 |
![Image result for electron shell with number model 2,8,8](https://www.s-cool.co.uk/assets/learn_its/gcse/chemistry/atomic-structure/atoms_/g-che-atomic-dia31.gif)
Relationship between electron shells and the periodic table
- The number of electrons in the outer shell is equal to the group number
- The number of shells is equal to the period.
![Image result for periodic table and electron shells gcse](https://i.ytimg.com/vi/EmsDo919FTc/maxresdefault.jpg)
Ions
Ions are elements which have had electrons added or removed, giving them a charge.
Cation vs Anion
Cation: An ion with less electrons than normally. It has a positive charge .
Anion: An ion with more electrons than normally. It has a negative charge.
Bonding
Types of bonding
Bonding name |
Type of elements |
Diagram |
Covalent |
Simple molecular |
Non-metal and Non-metal |
![Image result for covalent bond](https://ibrecap.com/images/user_images/blobid01554991249.png) |
Giant molecular |
Carbon or Silicon with itself. |
![Image result for giant covalent](https://ibrecap.com/images/user_images/blobid21554991394.png) |
Metallic |
Metal and Metal |
![Image result for Metallic bond](https://ibrecap.com/images/user_images/blobid11554991268.png) |
Ionic |
Non-metal and metal |
![Image result for Ionic bond diaGRAM](https://quatr.us/wp-content/uploads/2017/06/salt.jpg) |
Lewis structures
A lewis structure is a diagram specifically for Covalent bonding Which shows which electrons are shared in the bond of a molecule.
How to draw it:
- Start by drawing all the electrons as crosses around an element
- Then circle electron pairs to show that they are shared across the elements.
- Circle the electrons so that they add up to 8; a full shell.
- Neaten it up by replacing any pairs of electrons with a single line
Example diagram
![Image result for Lewis structure](https://ibrecap.com/images/user_images/blobid31554991641.jpg)
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