Lesson - 2.4.3

• Metal atoms are held together strongly by metallic bonding in a giant metallic lattice

• Within the metallic lattice, the atoms lose the electrons from their outer shell and become positively charged ions

• The outer electrons no longer belong to a particular metal atom and are said to be delocalised

• They move freely between the positive metal ions like a 'sea of electrons'

• Metallic bonds are strong and are a result of the attraction between the positive metal ions and the negatively charged delocalised electrons

Properties of Metals

• Metals have high melting and boiling points

  • There are many strong metallic bonds in giant metallic structures between the positive metal ion and delocalised electrons

  • A lot of heat energy is needed to break these bonds

• Metals conduct electricity

  • There are free electrons available to move through the structure and carry charge

  • Electrons entering one end of the metal cause a delocalised electron to displace itself from the other end

  • Hence electrons can flow so electricity is conducted

  • They can move as the intermolecular force gives more space to the electrons to move unlike atoms who are together with covalent bond which does not give electrons space to move around them thus electricity moves around metals but not atoms with covalent bond

• Metals are malleable and ductile

  • Layers of positive ions can slide over one another and take up different positions

  • Metallic bonding is not disrupted as the outer electrons do not belong to any particular metal atom so the delocalised electrons will move with them

  • Metallic bonds are thus not broken and as a result metals are strong but flexible

  • They can be hammered and bent into different shapes or drawn into wires without breaking