Metallic Bonding | Chemistry for Grade 11 (IGCSE) PDF Download

Metallic Bonding

• Metal atoms are strongly bound together through metallic bonding within a large metallic lattice.
• In this lattice, atoms release electrons from their outer shell, transforming into positively charged ions.
• The outer electrons no longer belong to individual metal atoms but move freely, known as delocalisation.
• These delocalised electrons drift amidst the positive metal ions resembling a 'sea of electrons'.
• The strength of metallic bonds originates from the attractive forces between positive metal ions and the negatively charged delocalised electrons.

Properties of Metals

Melting and Boiling Points

• Metals possess high melting and boiling points due to the presence of strong metallic bonds within their structures. 
• Significant heat energy is necessary to break these bonds.

Electrical Conductivity

• Metals conduct electricity because of the availability of free electrons that can move through the structure to carry charge. 
• When electrons enter one end of the metal, a delocalised electron displaces itself from the other end, facilitating the flow of electrons and the conduction of electricity.

Malleability and Ductility of Metals

• Positive ion layers have the ability to shift relative to one another, allowing for different arrangements.
• The integrity of metallic bonding remains intact because the outer electrons are not associated with specific metal atoms; consequently, the delocalized electrons move correspondingly.
• Due to this maintenance of metallic bonds, metals possess strength along with flexibility.
• Metals exhibit resilience, enabling them to endure processes like hammering, bending into diverse forms, or being drawn into wires without undergoing fracture.

Edurev Tip: When discussing the conductivity of metals, ensure clarity in the language employed and avoid confusion with ionic compounds. Metals conduct electricity due to the presence of unbound electrons capable of transporting charge, whereas molten or aqueous ionic compounds conduct electricity because they contain free ions that can carry charge.