Metals and Non-Metals: Properties, Reactivity, Alloys & Metallurgy

Metals and non-metals is a core chemistry topic for Kerala PSC. Questions cover properties, reactivity series, alloys, important ores, and corrosion. The tables below organize all frequently tested facts.

1. Physical Properties — Metals vs Non-Metals

Property	Metals	Non-Metals
State at room temperature	Solid (except Mercury — liquid)	Solid, liquid (Bromine), or gas
Lustre	Shiny (metallic lustre)	Generally dull
Malleability	Malleable (can be hammered into sheets)	Brittle
Ductility	Ductile (can be drawn into wires)	Not ductile
Conductivity (heat/electricity)	Good conductors	Poor conductors (except Graphite)
Sonority	Sonorous (produce sound when struck)	Non-sonorous
Melting/boiling point	Generally high	Generally low
Density	Generally high	Generally low

2. Exceptions to Remember

Exception	Detail
Mercury (Hg)	Metal that is liquid at room temperature
Gallium (Ga) and Caesium (Cs)	Metals with very low melting points (melt on palm)
Iodine	Non-metal with lustre
Graphite	Non-metal that conducts electricity
Diamond	Non-metal with highest hardness
Sodium (Na) and Potassium (K)	Metals that are soft (can be cut with a knife)
Tungsten (W)	Metal with highest melting point (3,422 degrees C)

3. Chemical Properties of Metals

Reaction	Example
Metal + Oxygen = Metal oxide	4Na + O2 = 2Na2O (sodium oxide)
Metal + Water = Metal hydroxide + Hydrogen	2Na + 2H2O = 2NaOH + H2
Metal + Acid = Salt + Hydrogen	Zn + H2SO4 = ZnSO4 + H2
Metal + Salt solution = Displacement	Fe + CuSO4 = FeSO4 + Cu

4. Reactivity Series of Metals

Position	Metal	Symbol	Reactivity
1 (Most reactive)	Potassium	K	Reacts violently with cold water
2	Sodium	Na	Reacts vigorously with cold water
3	Calcium	Ca	Reacts with cold water
4	Magnesium	Mg	Reacts with hot water/steam
5	Aluminium	Al	Reacts with steam
6	Zinc	Zn	Reacts with steam
7	Iron	Fe	Reacts with steam
8	Lead	Pb	Reacts with dilute acids
9	Hydrogen	H	(Reference point)
10	Copper	Cu	Does not react with dilute acids
11	Silver	Ag	Low reactivity
12	Gold	Au	Least reactive
13 (Least reactive)	Platinum	Pt	Least reactive

Mnemonic: Please Stop Calling Me A Zealous Iron Lover Having Copper Silver Gold Platinum

5. Important Ores of Metals

Metal	Ore	Chemical Formula
Iron	Haematite	Fe2O3
Iron	Magnetite	Fe3O4
Aluminium	Bauxite	Al2O3.2H2O
Copper	Copper Pyrite (Chalcopyrite)	CuFeS2
Zinc	Zinc Blende (Sphalerite)	ZnS
Zinc	Calamine	ZnCO3
Tin	Cassiterite	SnO2
Lead	Galena	PbS
Mercury	Cinnabar	HgS
Silver	Argentite	Ag2S
Gold	Calaverite	AuTe2
Manganese	Pyrolusite	MnO2

6. Important Alloys

Alloy	Composition	Use
Steel	Iron + Carbon (0.1-2%)	Construction, machinery
Stainless Steel	Iron + Chromium + Nickel + Carbon	Utensils, surgical instruments
Bronze	Copper + Tin	Statues, medals, bells
Brass	Copper + Zinc	Utensils, decorative items
Solder	Lead + Tin	Joining electrical wires
German Silver	Copper + Zinc + Nickel (no silver)	Utensils, ornaments
Duralumin	Aluminium + Copper + Manganese + Magnesium	Aircraft bodies
Nichrome	Nickel + Chromium + Iron	Heating elements
Amalgam	Mercury + Other metals	Dental fillings
Gun Metal	Copper + Tin + Zinc	Guns, gears, bearings

7. Metallurgy — Steps of Metal Extraction

Step	Process	Detail
1	Crushing and grinding	Ore broken into small pieces
2	Concentration (Ore dressing)	Removal of gangue (impurities)
3	Roasting	Heating sulphide ore in air (converts to oxide)
4	Calcination	Heating carbonate ore in absence of air (converts to oxide)
5	Reduction	Metal oxide reduced to metal (using carbon/coke or electrolysis)
6	Refining	Purification of crude metal (electrolytic refining)

8. Methods of Concentration

Method	Used For	Principle
Gravity separation	Heavy ores (tin, gold)	Density difference
Froth flotation	Sulphide ores (copper, zinc)	Wettability difference
Magnetic separation	Magnetic ores (magnetite)	Magnetic property
Leaching	Bauxite (Bayer’s process)	Chemical dissolution

9. Corrosion

Aspect	Detail
Definition	Gradual destruction of metal by chemical/electrochemical reaction with environment
Rusting	Corrosion of iron; requires both oxygen and moisture
Rust formula	Fe2O3.xH2O (hydrated iron oxide)
Prevention methods	Painting, oiling, galvanising (zinc coating), electroplating, alloying
Galvanisation	Coating iron with zinc; zinc corrodes preferentially (sacrificial protection)
Anodising	Electrolytic coating of aluminium with thick oxide layer

10. Non-Metals — Key Facts

Non-Metal	Key Property
Carbon	Exists as diamond (hardest), graphite (conductor), fullerene
Sulphur	Yellow solid; used in vulcanisation of rubber
Phosphorus	White phosphorus glows in dark; red phosphorus used in matchsticks
Nitrogen	78% of atmosphere; essential for proteins
Silicon	Semiconductor; used in computer chips
Chlorine	Greenish-yellow gas; used in water purification

11. Previous Year Question Patterns

• “Most abundant metal in Earth’s crust?” — Aluminium
• “Liquid metal at room temperature?” — Mercury
• “Brass is an alloy of?” — Copper and Zinc
• “Ore of aluminium?” — Bauxite
• “Galvanisation uses which metal?” — Zinc
• “German Silver contains?” — Copper, Zinc, Nickel (no silver)
• “Metal with highest melting point?” — Tungsten
• “Non-metal that conducts electricity?” — Graphite
• “Rusting requires?” — Both oxygen and moisture