Bonding

• electrostatic attraction • between oppositely charged ions

• electrostatic attraction • between shared pair of electrons • and nuclei of bonded atoms

• electrostatic forces acting in all directions • lots of energy required to overcome bonds • high mpt and bpt

• solid- ions held in fixed position • no mobile charge carriers • liquid- ions are mobile • able to conduct

• greater the ionic charge the less soluble an ionic compound • water can overcome ionic bonds • attracted to polar ions

• one atoms donates lone pair of electrons • electrostatic attraction between shared pair of electrons • and nuclei of bonded atoms

• triple bond between • lone pair on each

• double bond between CO • single between CH

• dative bond between N and B

• dative covalent bond • 1+ charge

• only have induced dipole-dipole forces • weak • require little energy to overcome • low mpt and bpt

• no mobile charge carrier, ions or electrons • can’t carry charge

soluble in non-polar solvents

• Si8 • graphite • diamond • graphene • silicon dioxide SiO2

• high • large number of covalent bonds • large amount of energy to overcome

• graphite and graphene can • delocalised electrons • free to carry charge

• electron pair repel each other round the central atom • depends on number and type of pairs • lone pairs repel more than bonded

linear 180°

Trigonal planar 120°

Tetrahedral 109.5°

Trigonal bipyramidal 120° and 90°

90°

trigonal pyramidal 107°

angular(bent) 104.5°