C2 structure,bonding and the properties of matter Flashcards
Ionic bonding
Metals and non metals
Partials are oppositely charged ions
Structure- large crystals made from ions attracted to each other by electrostatic attraction
Room temp- solids
Melting point- high
Conductor of electricity- not when solid, yes when molten
Covalent bonding
Compounds of non metals and in most non metallic elements
Atoms that share pairs of electrons
Structure- molecules made from atoms bonded by covalent bonds
Room temp- liquid and gases
Melting point- low
Conductor of electricity- no or very little
Very strong
Metallic bonding
Metallic elements and alloys
Atoms that share delecoalised electrons
Structure- lumps or sheets of metal made from atoms packed together so that the delocalised electrons move through the fixed position
Room temp- solids (expect Mercury liquid)
Melting point- high
Sharing delocalised electrons makes strong bonds
Conductor of electricity- yes, good conductor
When metals and non metals transfer electrons
Atoms become charged. Make ions. Metal is positively charged Non metal is negatively charged Ionic bonding Positive and negative attracted by electrostatic attraction
Why do atoms bond
To make stable electronic structures
It is easier for metals to lose electrons and become positive ions
And easier for non metals to gain electrons to become negative ions
Giant structures
An ionic compound is a giant structure of ions in a lattice
Ball and stick diagram pros
The structure in 3D
The charges on the ions
The arrangement of ions in 3D
The type of ions in all directions
Ball and stick cons
Ions are actually closer together
Gives false image of bond direction when it is only electrostatic attraction
Ball and stick best represents
The number and type of ions in 3D
Close packed pros
The structure in 3D The charges on the ions The arrangement of ions In 2D (look at the front face of the diagram) The closeness of ions
Close packed cons
Difficult to see arrangement of ions in 3D
Close packed best represents
The way that ions are packed close together
States of matter
Solid} sublimation} gas Gas} condensation} liquid Liquid} boiling} gas Liquid} freezing} solid Solid} melting} liquid
In melting and boiling
Forces between particles decrease
Distance between particles increases
Arrangement becomes more random
Particles move more so need more energy from surroundings
In freezing and condensing
The strength of the particles remains the same
Distance between particles decreases
Arrangement becomes less random
Particles move less so less energy required from surroundings
Limitations of simple model
There are no forces represented between spheres
All particles represented as spheres
The spheres are represented as solid and inelastic
Small molecule
2 or 3 atoms joined together with no charge
Relatively low melting points and boiling points
Weak intermolecular forces
Canβt conduct electricity as have no charge
Polymers
Very large molecules
Atoms are linked to other atoms by strong covalent bonds
Form long chains
Intermolecular forces between polymer molecules are weaker
Allow chains to slide over each other but not pulled apart