Bonding: Metallic Bonding

Question 1

Definition of Metallic Bonding

Answer 1

• Metallic bonding is an electrostatic force of attraction between the positively charged metal ions and the sea of delocalised electrons

Question 2

Structure of Metals

Answer 2

• Metal elements exist as giant metallic lattice structures
• The outermost shell of electrons of a metal atom is delocalised
• This leaves a positive metal ion and a sea of delocalised electrons

Question 3

Properties of Metallic Bonding: Melting Point

Answer 3

• Metals usually have high melting and boiling points due to the many strong electrostatic forces of attraction between the positive metals ions and the sea of delocalised electrons
• Requires a lot of energy to break these bonds

Question 4

Properties of Metallic Bonding: Factors Affecting Melting Point

Answer 4

• Charge on the metal ions

• Greater charge of a metal ion means it has more delocalised electrons
• This causes a greater attraction between the positive metal ions and the delocalised electrons, and the stronger the metallic bonds
• Resulting in a higher melting point

• Size of the metal ions

• The smaller the metal ion, the closer the positive nucleus is to the delocalised electrons
• This means there is a greater attraction between the two, which creates a stronger metallic bond
• Size of metal ions increase as you go down a group
• Size of metal ions decrease as you go across a period
• Although more electrons are being added to atoms, they are at similar distances to the nucleus; and the increasing nuclear charge “pulls” the electron clouds inwards, making the ionic radii smaller

Question 5

Properties of Metallic Bonding: Ability to be Shaped

Answer 5

• Malleable - can be shaped
• Ductile - can be drawn into wires
• There are no bonds holding specific ions together, so layers of metal ions can slide over each other without breaking the metallic bonds

Question 6

Properties of Metallic Bonding: Conductivity

Answer 6

• Metals are good conductors of electricity
- The ‘sea’ of delocalised electrons is able to move and carry a flow of charge

• Metals are good conductors of heat
- The delocalised electrons can pass kinetic energy to each other