C3 Structure and Bonding Flashcards
What are the three types of strong bonding?
Ionic,covalent and metalic
What is a metalic bond?
Electrostatic attraction between delocalised outer shell electrons and metal ions
Electrical conductivity of a metalic bond?
Good as a solid
Good as a liquid
What is an ionic bond?
Electrostatic attraction between oppositely charged ions
What is the electrical conductivity of an ionic bond?
Poor as a solid
Good as liquid or aqueous
What is a covalent?
Electrostatic attraction between a shared pair of electrons and the nuclei of two atoms
What is electrical conductivity of a covalent bond?
Poor as a solid (with some exceptions)
Poor as a liquid and gas
What are the three chemical structures?
- Giant (Metalic/Ionic/Covalent)
- Simple Molecular
- Monatomic
Which structure ONLY conduct as liquid?
- Giant Ionic
- Giant Covalent (graphite,diamond,SiO2)
What happens when elements react?
They form compounds by either: gaining, losing or sharing electrons
In Ionic bonding the particles are….
Oppositely charged ions.
In Covalent bonding the particles are….
non-metal atoms which share pairs of electrons
Properites of ionic compounds:
- High melting points
- Good conductors of electricity when melted or dissolved in water
Properties of Metalic bonds:
- High melting points
- Good conductors of heat and electricity in any state
What are the properites of small molecules?
- Low melting poins
- Poor conductors of electricty
Why are metalic bonds good conductors?
Structures contain charged particles (delocalised electrons) that can move through the whole structure
What are the carbon allotropes?
- Diamond
- Graphite
- Fullerene
Properties of diamond:
- Colourless, Transparent
- Lustrous (shiny)
- Hard
- Solid at room temperature
- Has 4 strong Covalent bonds per Carbon atom
Properties of graphite :
- Black , Opaque
- Lustrous
- Soft and slippery
- Solid at room temp
- Delocalised electrons, weak forces between layers
- 3 Strong Covalent bonds per Carbon atom
Fulleren properties :
- Dark
- Needle like crystals
- 3 strong covalent bonds per Carbon atom
How are atoms in metals arranged?
Closely packed together in regular layers
1 nanometre is …..
1x10^-9 meters
Billionth of a metre
What does prefix ‘nano-‘ mean?
Nano- means one billionth
Why is silver nanoparticles in socks?
Silver nano-particles have longer-lasting properties (such as anti-bacterial) than bigger particles of silver. That why they are used in socks to kill bacteria and prevent bad smells
What is the diameter of a nano particle?
1 - 100 nanometrs
1 x 10^-9 meters - 1 x 10^7 meters
What is the diameter of a fine particle?
100 - 2500 nanometers
(1x10^-7 - 2.5x10^-6 meters)
What is the diameter of coarse particles?
2500 - 10000 nanometers
2.5x10^-6 - 1x10^-5
Why are nanoparticles more useful?
They have a larger surface area to volume ratio
Uses of nanoparticles :
- Medicine : MRI scanning and cancer therapies
- Electronics : Used in memory chips
- Cosmetics : Used in skincare lotions to encapsule nutrients
- Sun Cream : Replaced zinc oxide to make it clear
- Deodorant : Silver has antibacterial properties
- Catalysts : Self-Cleaning windows
How to find the surface area to volume ratio?
Surface area to volume ratio = Surface area/Volume
What is the charge of a non-metal ion?
Negative (Gaining Electrons)
What is the charge of a metal ion?
Positive (Lose Electrons)
Uses of fullerene:
- Catalysts
- Reinforcements for composite material
- In drugs
What is graphene?
A single layer of graphite
What is the formula for buckminister fullerene?
C60
How can graphite conduct electricity?
Because delocalised electrons cam move through it’s layers
What makes metals malleable?
Layers of atoms in a metal can slide over
Why is graphite a good electrical conductor?
Only three electrons per carbon atom is used in covalent bonds so one electron is delocalised. These delocalised electrons can move through the whole structure carrying an electrical charge
Why is graphite soft and slippery?
It’s particles are in fixed layer with weak intermolecular forces between them.
This allows the layers to slide across each other easily.
