1.1 Making a Solid Flashcards
State the 6 types of matter
Crystals, molecular crystals, quasicrystals, liquid crystals, amorphous solids, liquids
When do you get ionic bonding?
When it is energetically favourable for an electron to be transferred from one atom to another
Describe the properties of an ionic bonding
Strong but brittle
High melting temperature
What type of material is typically formed by an ionic bond and why?
Insulator as electrons are held in place
State the three energies involved in the production of a bond and define them
Ionisation energy - Energy needed to remove one electron
Electron affinity - Energy gain from making a negative ion
Cohesive energy - Energy gain from adding/removing positive and negative ions
State the equation of the energy cost of an ionic bond, and when do we get an ionic bond?
ΔE = Ionisation E - Affinity E - Cohesive E
Get a bond when ΔE < 0
Describe a covalent bond
Shared valence electrons
Describe the properties of a covalent bond
Directional - non-ductile as the directionality of the orbitals hold the shape
What type of materials are usually formed by covalent bonds?
Semi conductors/insulators
Describe metallic bonding
When valence electrons are shared among all atoms
Describe the properties of a metallic bond
Bonds are non directional. Ductile
What type of materials are usually formed by metallic bonds?
Thermal and electrical conductors due to the delocalised electrons
Describe Van der Waals bonding
Bonding due to interaction between instantaneous electric dipoles on neighbouring atoms
Describe the properties of Van der Waals bonding
Weak but long range
Has a contribution in all solids
Describe mixed bonding
Bonding can be due to several processes in a material
