Chapter 3: Metals and Non-metals
Physical Properties of Metals vs Non‑Metals
Metals are typically lustrous, malleable (can be hammered into sheets), ductile (can be drawn into wires), and good conductors of heat and electricity. In contrast, non‑metals are usually dull, brittle (breakable), and poor conductors. Some exceptions exist—like graphite, which conducts electricity, and bromine, which is a liquid at room temperature.
Chemical Reactivity and Compound Formation
Most metals react with dilute acids to release hydrogen gas, as well as with oxygen to form basic oxides. Highly reactive metals like sodium and potassium also react with water. Non‑metals generally form acidic or neutral oxides. Certain oxides, such as aluminum oxide and lead oxide, behave amphoterically—reacting with both acids and bases.
Reactivity Series, Extraction, and Corrosion
The reactivity series ranks metals by how easily they lose electrons; it determines whether a metal can displace hydrogen from acids or displace another metal from its compound. Metals high in this series are extracted by electrolysis, while less reactive ones are obtained by reduction with carbon or carbon monoxide. Metals like iron corrode (rust) when exposed to moisture and oxygen; corrosion can be prevented by methods like painting, galvanization, or using alloys.