Ionic bonds

how are ions formed

• transfer of electrons from a metallic element to a non metallic element

• this leaves both elements with a full outer shell

• metals lose electrons to form cations, non-metals gain electrons to form anions

ionic bonding

• force of attraction between oppositely charged ions to form ionic compounds

• electrostatic attractions are formed between the oppositely charged ions

• this form of attraction is very strong

charge of ionic compounds

• electrically neutral, the positive charges equal the negative charges

• overall charge of an ionic compound is 0

ionic lattices

• ions in a lattice are arranged in a regular repeating pattern, so that positive charges cancel out negative charges

• lattice has an overall neutral charge

lattice enthalpy

• standard enthalpy change that occurs on the formation of 1 mole of gaseous ions from the solid lattice

• since this is an endothermic process, enthalpy change will always have a positive value

• the process is endothermic as energy is always required to break the bonds between the ions in the lattice

properties of ionic compounds

• high mpt/bpt

  • increases when charge density increases, when an ion is smaller it’s charge takes up more of its volume

  • this causes the ions to be more attracted to eachother, taking more energy to separate them

• conduct electricity when molten or aqueous as ions are able to move around

• soluble, can form ion-dipole bonds

• hard, brittle

• not volatile, large amnts of energy required to overcome large electrostatic forces of attraction