Metallic Bonding & Nanoparticles
Metallic bonding creates a "sea of electrons" - positive metal ions surrounded by delocalised electrons that can move freely. This explains why metals conduct electricity and heat so well, plus why they're malleable rather than brittle.
Metal alloys mix different metals ormetalswithnon−metals to create stronger materials. Different-sized atoms disrupt the regular arrangement, preventing layers from sliding over each other easily - that's why steel is harder than pure iron.
Nanoparticles 1−100nmdiameter have massive surface area to volume ratios, making them incredibly useful. They're revolutionising everything from medicine to electronics because their tiny size gives them unique properties.
Applications include drug delivery, computer chips, antibacterial deodorants, and surgical masks - their high surface area makes them excellent catalysts too.
Key Concept: Size matters! As particles get smaller, their surface area to volume ratio increases dramatically, creating new properties and applications.