Natural and Synthetic Materials
- We use a wide range of materials, including metals, ceramics and polymers.
- All are made of chemicals, either individual chemicals or mixtures of chemicals.
- Chemicals are made up of atoms/groups of atoms bonded together.
- Some materials are mixtures = different substances not chemically bonded together.
- Synthetic means man made materials.
Different materials have different properties
Different properties -
- Melting points (temperature solid truns to liquid).
- Strength (how good at resisting force) ---> tension (resist pulling) and compressive (resist push).
- Stiffness (not bending when force applied).
- Hardness (difficulty of cutting it).
- Density (mass per unit volume).
Materials, properties and uses
Possible uses for material depend on its properties - e.g. plastics, fairly hard, strong and stiff with a low density.
The effectiveness of a product is how good it it at the job it's meant to do. A products effectiveness depends on the materials it's made from. Materials also effect a product's durability - how long it will last.
By looking at properties, we can decipher whether it is suitable for its purpose.
Crude oil and its uses
Crude oil a mixture of hydrocarbons. Hydrocarbons are molecules made of carbon and hydrogen atom chains.
As length of carbon chain changes, the properties of the hydrocarbon change. Short-chain = lower boiling points. Long chains = high boiling points.
Two types of bond in crude oil =
- Strong covalent bonds between carbons and hydrogens within each hydrocarbon molecule.
- Intermolecular forces of attraction between different hydrocarbon molecules in the mixture.
- Crude oil is heated - molecules have more energy.
- Molecules move more, overcome intermolecular forces.
Covalent bonds are much stronger than the foces, so bonds don't break. Forces break easier in small molecules.
The process of seperating…