Why can metals be hammered into sheets and conduct electricity, while an ionic crystal like salt just shatters?
A metal is a lattice of positive ions in a 'sea' of delocalised electrons; when you hammer it, layers slide but the electron sea keeps holding them together, so it bends and flattens, and those mobile electrons carry current.
A metal is a lattice of positive ions in a 'sea' of delocalised electrons; when you hammer it, layers slide but the electron sea keeps holding them together, so it bends and flattens, and those mobile electrons carry current. In an ionic solid, ions are locked in a rigid lattice; shift a layer and like charges line up, repel, and the crystal cleaves. Its ions only move (and conduct) when melted or dissolved.
Key point
Free electrons make metals malleable and conducting; rigid ion lattices make salts brittle and non-conducting when solid.
Common mistake
expecting ionic solids to conduct electricity in the solid state.
Memory tip
electron sea = bendy + conductive; fixed ion lattice = brittle + insulating (until molten).
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