International General Certificate of Secondary Education (IGCSE) Chemistry Practice Exam

What is metallic bonding defined as?

1. The attraction between non-metal atoms

2. The electrostatic attraction between an array of positive ions and delocalised electrons

3. The sharing of electrons between atoms

4. Forces between molecules

The correct answer is: The electrostatic attraction between an array of positive ions and delocalised electrons

Metallic bonding is characterized as the electrostatic attraction between an array of positive ions and delocalised electrons. In a metallic structure, metal atoms lose some of their electrons, allowing these electrons to move freely throughout the lattice. This movement of delocalised electrons is responsible for several properties of metals, including electrical conductivity, malleability, and ductility. The presence of positively charged metal ions and the cloud of delocalised electrons which surround them creates a strong bond that holds the structure together. This bond results in a rigid structure that can also allow atoms to slide past one another without breaking the metallic bond, which contributes to the malleability of metals. In contrast, the other definitions provided do not accurately describe metallic bonding. The first choice refers to non-metal atoms, which is irrelevant in the context of metallic bonding. The sharing of electrons pertains to covalent bonding, not metallic. Lastly, forces between molecules describe intermolecular forces, such as van der Waals or hydrogen bonding, which do not apply to the unique structure and bonding seen in metals.