bonding and structure Flashcards
ionic bond
the attraction between oppositely charged ions
structure of an ionic compound
ionic lattice
properties of ionic compounds
- high melting and boiling points- strong ionic bonds that require a lot of energy to break
- cannot conduct electricity when solid, only when liquid- when solid, ions are not free to move and carry charge
when liquid, ions are free to move and carry charge
ionic bonding occurs between __________________________________
a metal and non-metal
how is an ionic bond formed
electrons are transfered from the metal to non-metal
definition of a covalent bond
a shared pair of electrons
definition of a molecule
2 or more atoms covalently bonded together
definition of diatomic
2 atoms covelantly bonded in a molecule
what types of elements are present in substances which contain covalent bonds
non-metals
2 types of covelant bonds
simple and giant
why do simple covelant substances have low melting and boiling points
have weak van der waals’ forces between the molecules which require little energy to break
why are simple covelant substances poor conductors of electricity
thye do not have delocalised electrons that can move and carry charge
properties of simple covelant substances
- low melting and boiling points
- they are soft and brittle
- poor conductors of electricity
- insoluble in water
examples of giant covelant structures
graphite
graphene (one layer of graphite)
diamond
why do giant covalent structures have hight melting and boiling points
have strong covelant bonds which require lots of energy to break