Properties of Metals | Chemistry for Grade 11 (IGCSE) PDF Download

Physical Properties of Metals & Non-Metals

Metals and non-metals

• The Periodic Table contains over 100 different elements
• They can be divided into two broad types: metals and non-metals
• Most of the elements are metals and a small number of elements display properties of both types. These elements are called metalloids or semimetals.
• The metallic character diminishes moving left to right across the Periodic Table:
  

Properties of Metals

• Metals can conduct heat and electricity.
• They are malleable, meaning they can be hammered into different shapes, and ductile, meaning they can be drawn into wires.
• Metals tend to be lustrous, giving them a shiny appearance.
• They have high density and usually high melting points.
• Metals form positive ions through the loss of electrons and produce basic oxides.

Properties of Non-Metal Elements

• Non-metals do not conduct heat and electricity.
• They are brittle when solid and easily break up.
• Non-metals tend to be dull and nonreflective.
• They have low density and low melting points, with many being gases at room temperature.
• Non-metals form negative ions through electron gain (except for hydrogen) and create acidic oxides.

Chemical Properties of Metals

• Metals possess specific chemical characteristics
• Understanding metal chemistry involves examining reactions with water, dilute acid, and oxygen
• These reactions help establish a reactivity series of metals

Reactivity with Water

• Some metals react with water, producing a metal hydroxide and hydrogen gas
• For instance, calcium reacts with water to form calcium hydroxide and hydrogen gas:
  • Ca (s) + 2H₂O (l) → Ca(OH)₂ (aq) + H₂ (g)
• Other metals, like zinc, react with steam to form metal oxide and hydrogen gas:
  • Zn (s) + H₂O (g) → ZnO (s) + H₂ (g)

Reactivity of Metals with Acids

• Most metals, like iron, react with dilute acids, for example, hydrochloric acid (HCl).
• During the reaction between acids and metals, the metal atom replaces the hydrogen atom in the acid, resulting in the formation of a salt and hydrogen gas.
• Example: Iron:

  metal + acid → salt + hydrogen
  Fe (s) + 2HCl (aq) → FeCl₂ (aq) + H₂ (g)

Reactivity of Metals with Oxygen

• Unreactive metals such as gold and platinum do not react with oxygen.
• Some reactive metals, like the alkali metals, readily react with oxygen.
• Metals like copper and iron can also react with oxygen, but at a slower rate.
• When metals react with oxygen, they form metal oxides.
• Example: Copper:
  metal + oxygen → metal oxide
  2Cu (s) + O₂ (g) → 2CuO (s)