Topic 2- Bonding Structure And The Properties Of Matter Flashcards
Ionic
Opposite charged ions
Metal + non metal
Charge of ion relates to group number
Giant structure = lattice
Strong electrostatic forces
Covalent
Share electrons
Non metal + non metal
Strong bonds
Small molecules
Giant covalent
Diamond = carbon
Graphite = carbon
Silicon dioxide = silicon + oxygen
Metallic
Share delocalised electrons
Metal + metal
Giant structure in regular patterns
Strong bonds
The three states
Solid
Liquid
Gas
Melting point
Temperature a substance melts or freezes
Boiling point
Temperature a substance boils or condenses
Change in states
Amount of energy needed depend on strength of forces between particles
Stronger forces = more energy needed to change state
State symbols
Solids = (s)
Liquid = (l)
Gas = (g)
Aqueous = (aq)
Ionic compounds
Regular structure
Electrostatic forces of attraction between charged ions
High melting point
Conduct electricity when dissolved in water or melted
Covalent molecules
Usually gases or liquids
Low melting point
Weak intermolecular forces
Larger the molecules = stronger the forces
Polymers
Large molecules
Strong covalent bonds
Intermolecular forces relatively strong
Solid at room temperature
Giant covalent structures
Solids
High melting points
Strong covalent bonds
Metallic structures
Strong metallic bonds
Nigh melting points
Pure metals = layers+ can be bent and shaped
Alloys = mixture of metals = stronger
Metals
Good conducteurs of electricity and thermal energy
Delocalised electrons carry charge
Diamond
Each carbon forms 4 covalent bonds
Giant covalent structure
Hard
High melting point
Doesn’t conduct electricity
Graphite
Each carbon forms 3 covalent bonds
Forms layers of hexagonal rings
No covalent bonds between layers
Some delocalised electrons
Graphene
One layer of graphite
Useful in electronics and composites
Fullerenes
Molecules of carbon atoms with hollow shapes
Based on hexagonal rings of carbon
First fullerene discovered = buckminsterfullerene
Carbon nanotubes
Cylindrical fullerenes
Very high length to diameter ratio
Useful for nanotechnology electronics and materials
Nanoscience
Structures between 1-100nm in size
Nanoparticles
Smaller than fine particles
Diameters between 100-2500nm
May have different properties from those from the same material
Smaller quantities needed to be effective
Used in medicine, electronics, cosmetics, deodorants and as catalysts
Coarse particles
Diameter between 110^5-2.510^6
Often refer to as dust
Surface area : volume
As the side of a cube decreases by a factor of 10 the surface area to volume ratio increase by a factor of 10
