C2 Flashcards
(43 cards)
Definition of melting point?
The temperature a which a solid turns into a liquid
What is density?
Mass of a given volume of the material
When should outliers be discarded?
Only if there was an error in the measurement.
How do you get the true value?
By calculating the mean
Name 3 properties of metals
Shiny, malleable, and electrical conductors
Can all metals conduct electricity?
YES!!!
What are Natural materials?
Materials from living things which require little processing.
Give 2 examples of natural materials?
Silk and wool
What are Synthetic materials?
Materials that are manufactured by chemical reactions using raw materials.
Why have synthetic materials replace natural materials?
- Some natural materials are in short supply
- They can be designed to give particular properties
- They are cheaper and can be made in quantity needed
What are hydrocarbons made of?
Hydrogen and Carbon atoms
What is crude oil made up of ?
A Mixture of hydrocarbons
How do you seperate crude oil?
Using fractional distillation
How does FD seperate crude oil?
It seperates them using boiling points
As the hydrocarbon chain length increases…
The forces between these molecules increase.
Why do larger molecules have higher boiling points
Because they need more energy to break intermolecular forces
The smaller the molecule chain…
the lower the boiling point.
What is a polymer?
A chain of monomers
What is the process that makes a polymer?
Polymerisation
When are the forces strongest?
The closer they are, the stronger they are.
The stronger the force…
The more energy is needed to seperate the molecules and the higher the melting point.
What does LDPE stand for?
Low density polyethene
What are the properties of LDPE ?
LDPEs have BRANCHES which make the intermolecular forces weak
What are the properties of HDPE?
HDPEs Dont have branches which makes the intermolecular forces strong