Properties of Metals

Physical Properties of Metals

• High melting and boiling points due to stable, compact and closely-packed structure.
• Solid at room temperature, except mercury which is a liquid.
• Dense nature with heaviness being a characteristic trait.
• Good conductors of heat and electricity because of free electrons that can move throughout the metal.
• Typically shiny, a property also known as metallic lustre.
• Ductility allows them to be drawn into thin wires.
• Malleability means they can be hammered or rolled into thin sheets.

Chemical Properties of Metals

• Exhibit property of losing electrons to form positive ions or cations.
• Easily combine with non-metals to form ionic compounds.
• Most metals react with oxygen to form metal oxides, which are basic in nature.
• Metals like potassium, sodium, calcium react with water to produce hydrogen gas.
• More reactive metals, like potassium, sodium, and calcium, displace hydrogen from water or acids.
• Less reactive metals, like gold and platinum, are found in nature in their native state.

Reactivity Series of Metals

• Metals can be arranged in a series known as the reactivity series according to their reactivity.
• Potassium, sodium, and calcium are more reactive than other metals.
• Gold and platinum are least reactive; almost resistant to chemical reaction under normal circumstances.
• Displacement reactions in metals can be predicted using the reactivity series.
• Reduction reactions occur when more reactive metals displace less reactive metals from their ores.

Extraction of Metals

• Less reactive metals can be found as elements, but most are found as ores, which are minerals containing the metal combined with other elements such as oxygen or sulphur.
• Extraction methods depend on a metal’s position in the reactivity series. Metals higher in the series, such as aluminium and iron, have to be extracted using electricity in a process called electrolysis.
• Less reactive metals, such as copper, can be extracted by reduction with carbon.
• Metal ores near the bottom of the reactivity series, such as gold, may be extracted using simple methods like washing.

Uses of Metals

• Metals can be used for a variety of purposes based on their properties. For example, copper is widely used in electrical wires because of its good conductivity.
• Aluminium, because of its lightness and resistance to corrosion, is used in aerospace industry.
• Steel, an alloy of iron, is used in construction for its strength and durability.
• Precious metals like gold and platinum are used in jewellery due to their lustre and resistance to tarnish.