17/01/2026
🧪 METALS AND NON-METALS
What are Metals?
Metals are substances that generally lose electrons and form positive ions (cations).
General Nature:
• Hard (except sodium, potassium)
• Shiny in appearance
• Good conductors of heat and electricity
• Mostly solids at room temperature
👉 Metals are electropositive in nature.
Physical Properties of Metals:
• Lustrous (shiny surface)
• Malleable (can be beaten into sheets)
• Ductile (can be drawn into wires)
• Sonorous (produce ringing sound)
• High melting and boiling points
⚠️ Exceptions:
• Sodium and potassium are soft
• Mercury is liquid at room temperature
What are Non-Metals?
Non-metals are substances that generally gain electrons and form negative ions (anions).
General Nature:
• Dull appearance
• Poor conductors of heat and electricity
• Can be solid, liquid, or gas
👉 Non-metals are electronegative in nature.
Physical Properties of Non-Metals:
• Not lustrous (except iodine)
• Not malleable or ductile
• Non-sonorous
• Low melting and boiling points
⚠️ Exception:
• Graphite conducts electricity
• Bromine is liquid at room temperature
Difference Between Metals and Non-Metals:
• Metals lose electrons, non-metals gain electrons
• Metals form basic oxides, non-metals form acidic oxides
• Metals conduct electricity, non-metals mostly do not
Chemical Properties of Metals
Reaction with Oxygen:
• Metals react with oxygen to form metal oxides
• Metal oxides are basic in nature
Example:
Magnesium + Oxygen → Magnesium oxide
⚠️ Some metal oxides are amphoteric
(They show both acidic and basic behaviour)
Chemical Properties of Non-Metals
Reaction with Oxygen:
• Non-metals react with oxygen to form non-metal oxides
• These oxides are acidic in nature
Example:
Sulphur + Oxygen → Sulphur dioxide
Corrosion:
Corrosion is the slow eating up of metals by air, moisture, or chemicals.
• Rusting is corrosion of iron
• Rusting requires air and water
👉 Corrosion weakens metals and causes loss.
Prevention of Corrosion:
• Painting
• Oiling and greasing
• Galvanisation
• Alloying
Uses of Metals:
• Iron → construction, tools
• Copper → electrical wires
• Aluminium → utensils, aircraft
• Gold → jewellery
Uses of Non-Metals:
• Oxygen → respiration
• Nitrogen → fertilizers
• Sulphur → medicines
• Chlorine → water purification
🛑Clean Concept Lines:
• Metals lose electrons
• Non-metals gain electrons
• Metal oxides are basic
• Non-metal oxides are acidic
• Rusting is corrosion of iron
• Corrosion causes damage