A giant ionic lattice structure
Ionic compounds have a giant ionic lattice structure
The ions form a closely packed regular lattice arrangement
- There are very strong electrostatic forces of attraction between the oppositely charged ions
- They all have high melting points and high boiling points ---> the strong forces as it takes a lot of energy to break them
- The solid ionic compounds cannot conduct electricity as the ions are not free to move so they cannot carry the current through the compound
- When the compound is melted, the ions are free to move in the solution, so they can conduct electricity
Long chains of repeating units that are joined together by strong covalent bonds
The intermolecular forces between polymer molecules are larger than between simple covalent molecules as more energy is needed to break them
The intermolecular forces are still weaker then ionic or covalent bonds
Giant Covalent Structures
- All the atoms are bonded together with strong covalent bonds
- Very high melting and boiling points as there is a lot of energy required to break the strong bonds between the atoms
- They do not contain charged particles so they do not conduct electricity, except graphite
- Examples of giant covalent structures are diamond, graphite and silicon dioxide.
- These are all made from carbon atoms, though silicon dioxide also contains oxygen
- Each carbon atom has four covalent bonds
- Very hard
- The strong covalent bonds take a lot of energy to break - high melting point
- No free electrons - does not conduct electricity
- Each carbon atom has three covalent bonds.
- It has sheets of carbon atoms arranged in hexagons.
- There are no covalent bonds between the sheets so they can move over each other, making it slippery - good lubricant.
- High melting point.
- Each carbon atom has one delocalised electron - it conducts electricity.
- One sheet of graphite is called graphene.
- Fullerenes are molecules of carbon that are hollow tubes or balls.
- They can be used to cage other molecules as they can be trapped inside the hollow part, an example would be a drug.
- A large surface area so they help to make catalysts and lubricants.
- They can also form nanotubes which are incredibly small carbon cylinders.
- They can conduct electricity and are rather flexible.
- Nanotubes are often used to make technology as they are so small and have a very small mass.
Nanoparticles have a diameter between 1nm and 100nm (1nm = 1x10-9). Nanoparticles have a large surface area to volume ratio because when particles decrease in size, their surface area increases.
- Catalysts - large surface area to volume ratio
- Drugs - absorb the drug easily
- Electric circuits - some can conduct electricity
- Surgical masks and wound dressings - antibacterial properties
- Cosmetics - reduce oil
- Sun cream - can protect the skin from UV rays and better coverage
Written by Bryant Wong (Chemistry)
- Share Education, https://shareeducatonideas.com/ionic-compound/
- Wikipedia, https://tr.wikipedia.org/wiki/Fulleren