Bonding

• Ionic bonding is the transfer of electrons between two atoms. This is usually between a metal and a non-metal.
• Covalent bonding is the sharing of electrons between non-metals.
• Positive ions are positive because there is now one less electron, meaning there is one more proton.
• Negative ions are negative because there is now one more electron than protons.
• Weak intermolecular forces of attraction occur in covalent bonding.
• Strong electrostatic forces of attraction occur in ionic bonding. Metal atom= positive, non-metal atom= negative. Electrostatic is strong because it is attraction between opposites
• In ionic bonding, they have high melting and boiling points because they have strong forces of electrostatic attraction. This means more energy is needed to overcome the strong forces to break apart the bonds.
• Ionic compounds conduct electricity when molten or dissolved as they contain charged particles that can move freely
• In covalent bonding, atoms have low melting and boiling points. This is because their weak intermolecular forces don’t need much energy to overcome them, so less heat is needed to change it’s state.
• In covalent bonding, the atoms never conduct heat or electricity.
• Metallic bonding occurs between metals.
• The regular arrangements of the metal ions mean that they are able to slide over each other, making them malleable and ductile. Malleable= bendy, ductile= can be drawn into wires.
• Metals have delocalised electrons, meaning that they are good conductors of electricity and heat because the delocalised electrons can carry a charge.
• Alloys are mixtures of metals that have been mixed with other elements to make them stronger.
• Alloys have different sized particles that disrupt their regular arrangement, which means the layers cannot slide over each other. This means that alloys cannot be bent or drawn into wires, making them stronger than metals.
• In dot and cross diagrams, group 7 always have 3 lone pairs.
• In dot and cross diagrams, hydrogen and carbon never have any lone pairs.
• In dot and cross diagrams, nitrogen always has one lone pair.