Structure and Bonding - C3 Flashcards
What are the states of matter
Solid
Liquid
Gas
Aqueous solution
What is formed when two elements ionically bond
two ions
Describe ionic bonding
Between a metal and a non-metal
Ions are formed
Strong bonds formed
Describe covalent bonding
Between 2 non-metals
Share electrons
Not as strong bonds
What is an allotrope
It is the same element but has a different structure at the same temperature
Name the giant covalent structures made from carbon
Diamond
Graphite
Describe the structure of diamond
Each atom forms 4 covalent bonds with other carbons They are in a tetrahedral structure This makes it very stable and hard Very high melting point Non - Conductor
Describe the structure of Graphite
Each atom forms 3 covalent bonds with other carbons
Layer structure - bonds beween the layers are weak
4th electron from each atom is delocalised - conductor
Very high melting point
Very soft - layer structure
Fairly unreactive
What is a fullerene of carbon
Describe the structure
They are large molecules of carbon with 60+ carbon atoms
They can be many different shapes like tubes or spheres
They are hollow
Each atom forms 3 covalent bonds with other carbons
4th electron delocalised - conductor
Used as reinforcement or as drug transport
What is Graphene
It is a single layer of graphite
Excellent electrical conductor
Very strong
Describe a metals structure
There is a sea of delocalised outer shell electrons
These surrond the positively charged ions
Metals are crystalline
Properties can be changed by changing the size of the crystals
How big is a nano meter
10 -9 of a meter
Why do nano-particles behave differently
Because they are so small
Their surface area is very big conpared to their volume
Uses of nanoparticles
Suncream
Delivering drugs to specific places in the body
Reinforce materials
Dangers of nanoparticles
Very explosive
Finding their way into the atmosphere and the enviorment
Could be dangerous if breathed in
