2.2.2 structure types Flashcards
Monatomic substances
Group 0 elements
Simple molecular substances
Elements: H2 O2 N2 F2 Cl2 Br2 I2 S8 P4
Compounds: non-metal with non-metal
Giant covalent substances
Elements: Si, diamond, graphite, graphemes
Compounds: SiO2
Ionic substances
Compounds: metal and non-metal
Metallic substances
Elements: Metals
Monatomic structure
Individual atoms with very weak forces between them
Simple molecular structure
Lots of individual molecules with weak forces between the molecules
(the atoms within molecules are joined by covalent bonds)
Giant covalent structure
Lattice structure in which all atoms are joined together in a giant network by covalent bonds
Ionic structure
Lattice structure of positive and negative ions
The ions are held together by the strong electrostatic attraction between the + and - ions, known as ionic bonding
Metallic structure
Lattice structure of metal atoms where the outer shell electrons from each atom are delocalised
There is a strong attraction between the positive nucleus of the atoms and the cloud of negative delocalised electrons (metallic bonding)
Monatomic bonding
None
Simple molecular bonding
Covalent (within molecules)
Giant covalent bonding
Covalent
Ionic bonding
Ionic
Metallic bonding
Metallic
Simple molecular formula (molecular)
Gives number of atoms of each type in one molecule
E.g. glucose C6H12O6
Each molecule contains 6C, 12H and 6O atoms
Monatomic empirical formula
Just the symbol
E.g. Ar
Simple molecular formula (empirical;)
Gives ratio of atoms in substance
E.g. glucose CH2O
Ratio of C:H:O atoms is 1:2:1
Giant covalent formula (empirical)
Gives ratio of atoms in substance
E.g. SiO2
Ratio of Si:O atoms is 1:2
Ionic formula (empirical)
Gives ratio of ions in substance
E.g. MgCl2
Ratio of Mg2+:Cl- ions is 1:2
Metallic formula (empirical)
Just the symbol
E.g. Fe
Monatomic M&BP
Very low due to very weak forces between atoms
Monatomic
Higher M&BP occur when
The heavier the atoms, the stronger the forces between the atoms, resulting in higher M&BP
Simple molecular M&BP
Low due to weak forces between the molecules
The atoms within the molecules are held together by strong covalent bonds, but these do not break when molecules melt/boil
Simple molecules
higher M&BP occur when
The stronger the intermolecular forces
Giant covalent M&BP
Very high due to large amount of covalent bonds
Giant covalent
Higher M&BP occur when
The stronger the covalent bonds
Ionic M&BP
High due to strong electrostatic attraction between positive and negative ions
Ionic
Higher M&BP occur when
The smaller the ions and the higher the charge on the ions the stronger the attraction between the positive and negative ions
Metallic M&BP
High due to strong electrostatic attraction between positive metal ions and delocalised negative electron
Metallic
Higher M&BP occur when
The smaller the ions, the higher the charge on the ions
the more delocalised electrons, the stronger the metallic bonding
Monatomic conductivity
Do not conduct
Contain no mobile ions or electrons
Simple molecular conductivity
Do not conduct
Contain no mobile ions or electrons
Giant covalent conductivity
Diamond, Si, SiO2
Do not conduct as they contain no mobile ions or electrons
Graphite, graphene
Conduct as delocalised electrons carry charge through structure
Ionic conductivity
Solids
Do not conduct as ions are not mobile
Liquids and solutions
Conduct as mobile ions carry charge through structure
Metallic conductivity
Conduct as delocalised electrons carry charge through structure
Monatomic solubility (aq)
Insoluble
Simple molecular solubility (aq)
Insoluble (usually)
Giant covalent solubility (aq)
Insoluble
Ionic solubility (aq)
Soluble (usually)
Metallic solubility (aq)
Insoluble
