found in compound ions (three dimensional structure consisting uncountable alternating positive / negative ions)
high melting / boiling point ionic compound 

electrostatic attractive force between the postive and negative ions is very strong so more energy is needed to overcome it thus requires high melting / boiling point
conducting electricity
ionic compound conduct in aqueous / molten solution due to presence of mobile ion
element
pure substance that cannot be broken down into 2 or more simple substance by chemical methods
elements exist as atoms or molecule
metal exists as atoms
non-metal exist as molecule
metalloids have properties of metal and non-metal
compound
a pure substance containing 2 or more different elements chemically combined in a fixed ratio
either covalent or ionic compounds
compound
different properties from the element that form it
can be separated into their constituents by :
exposing the compound to strong heat(thermal decomposition)
passing an electric current through the compound (electrolysis)
mixtures
do not have substances in fixed ratio
consist of elements / compounds
mixtures
physically combined
can be separate using techniques such as :
filtration
chromatography
distillation
physical properties of ionic substances
hard but brittle
most ionic substances are soluble in water and insoluble in organic solvent (alcohol)
when dissolved in wate , they are said to be in aqueous state
