Ionic bonding

• Ionic compounds have high melting and boiling points due to the strong electrostatic forces between ions.
• Metals are good conductors because they contain delocalised electrons that can move freely through the metal structure.
• The lattice energy is the amount of energy required to break all the ionic bonds in one mole of an ionic compound, forming gaseous ions.
• The number of electrons gained/lost by an atom determines the charge on its ion.
• Metals tend to form positive ions, while non-metals tend to form negative ions.
• Ions are charged particles formed when atoms gain or lose electrons.
• Ionic compounds have high electrical conductivity when dissolved in water or melted.
• In an ionic compound, there is no net charge on the molecule or formula unit.
• When two metals react with each other, their outer shell electrons combine to form metallic bonds.
• Group 1 elements lose their outermost electron(s) when forming positive ions (cations).
• Group 1 metals lose their outermost electron(s) to become positively charged ions (cations).
• Group 2 metals also lose two or three electrons from their valence shell to become doubly or triply charged cations.
• Group 7 elements gain one electron to become negative ions (anions), while Group 6 elements gain two electrons to achieve a full octet.
• Non-metal atoms gain enough electrons to fill their outermost shell with eight electrons, becoming negatively charged ions (anions).
• Cations are positively charged ions, while anions are negatively charged ions.
• A metal can be represented as M+ (positive) and a non-metal as N- (negative).