Explain why metals conduct electricity using delocalised electrons as mobile charge carriers.

In the subtopic Metals as conductors, this learning objective focuses on explain why metals conduct electricity using delocalised electrons as mobile charge carriers. Within How bonding and structure are related to the properties of substances, students should explain this idea in the exact curriculum context rather than as an isolated fact. Approved keywords for this objective include delocalised electron and charge carrier. delocalised electron means an electron that is not associated with a single atom or bond and can move freely within a metallic structure, allowing for electrical conductivity. Avoid students often confuse the mobile charge carriers in metals with those in ionic compounds, thinking both use ions to conduct electricity; instead clarify that in metals, delocalised electrons are the mobile charge carriers, while in ionic compounds, mobile ions conduct electricity. For exam answers, focus on how delocalised electrons act as mobile charge carriers in metals to explain their conductivity.