Metals and Non-Metals Overview

What are Metals and Non-Metals?

• Metals are elements that can lose electrons from their outermost shell.
• Non-metals are elements that can gain electrons from their outermost shell.
• Metalloids have properties of both metals and non-metals.
• Noble Gases have a completely filled outermost shell; they neither lose nor gain electrons.

Physical Properties of Metals and Non-Metals

• Malleability: Ability to be hammered into thin sheets; most metals are malleable, but exceptions exist.
  • Exceptions: Arsenic and Mercury
• Ductility: Ability to be drawn into thin wires; most metals are ductile, but exceptions exist.
• Hardness: Most metals are hard, but exceptions exist.
  • Exceptions: Sodium and Potassium (can be cut with a knife)
• Sonority: Ability to produce a ringing sound when struck; most metals are sonorous, but Mercury is an exception.
• Lustre: Ability to shine or reflect light; most metals are lustrous, but some non-metals are lustrous.
  • Exceptions: Iodine and Graphite
• Melting and Boiling Point: Metals generally have high melting and boiling points, but some exceptions exist.
  • Exceptions: Gallium and Cesium (melt at room temperature)
• Electrical Conductivity: Most metals are good conductors of electricity, but exceptions exist.
  • Exceptions: Mercury and Lead
• Thermal Conductivity: Most metals are good conductors of heat, but exceptions exist.
  • Exception: Graphite
• State: Most metals are solid at room temperature; Mercury is liquid. Non-metals exist in solid, liquid, or gaseous states at room temperature.
• Density: Metals are denser than non-metals, with an exception for Mercury.
  • Exceptions: Mercury (a liquid at room temperature.)

Chemical Properties of Metals and Non-Metals

• Reaction with Oxygen: Metals react with oxygen to form metal oxides.
  • High Reactivity Metals: Sodium and Potassium react rapidly with oxygen.
  • Low Reactivity Metals: Iron reacts slowly with oxygen.
  • Amphoteric Metals: Form both acidic and basic oxides.
    • Amphoteric Example Metals: Beryllium, Zinc, Tin, Lead, Aluminium, and Antimony ("Sub-Jane Padho Likho Aur BanoJanab")
• Reaction with Water: Most metals react with water to form metal hydroxides.
  • Highly Reactive Metals: Sodium reacts explosively with cold water.
  • Less Reactive Metals: Aluminium reacts with steam (hot water).
  • Least Reactive Metals: Gold does not react with water.
  • Non-Metals: Non-metal oxides react with water to form acids.
• Reaction with Acids: Metals react with dilute acids to form salts and hydrogen gas.
  • Nitric Acid (HNO3): A strong oxidizer; does not release hydrogen in most reactions.
    • Exceptions with HNO3: Magnesium and Manganese.
• Aqua Regia: A highly corrosive mixture (conc. nitric acid and hydrochloric acid, 1:3 molar ratio) used to dissolve noble metals (gold and platinum).

Reactivity Series

• Reactivity Series: A series of metals arranged by decreasing reactivity. Used to predict if one metal will displace another in a salt solution.
• Memory Aid: "Katerina ne Car maangi Alto, Jan (Sangeet) Cold Water ko bhi Denge na to bhi ye bade Khatarnaak Tarike se React Karenge!"

Metallurgy

• Metallurgy: The science and technology of extracting metals from ores and processing them into desirable forms.
• Minerals: Naturally occurring elements or compounds in the Earth's crust.
• Ores: Minerals from which metals can be extracted economically.
• Gangue: Impurities in the ore.

Methods of Extraction of Metals

• Enrichment of Ore: Removing gangue from ore.
• Extraction of Metals:
  • Low Reactive Metals (e.g., Copper):
    • Roasting: Heating the ore with oxygen to convert sulfide to metal oxide.
    • Reduction: Reducing the metal oxide to get the pure metal.
    • Refining: Removing impurities from the extracted metal.
  • Mid Reactive Metals (e.g., Zinc):
    • Roasting (sulfide ores): Same as for low reactive metals.
    • Calcination (carbonate ores): Heating the ore in the absence of air.
    • Reduction: Similar to low reactive metals.
    • Refining: Removing impurities.
  • High Reactive Metals (e.g., Sodium):
    • Electrolysis: Using electric current to extract the metal from a molten salt.
    • Refining: Similar to other refining methods.

Important Points to Remember

• Reactivity series determines the extraction method.
• Roasting, calcination, and reduction are key steps in extraction.
• Electrolysis is a vital method for extracting highly reactive metals.
• Refining is the final step for purity.

Extraction of Metals

• Zinc Oxide Extraction: Heating zinc sulfide in air to produce zinc oxide and sulfur dioxide.
• Reduction: Removing oxygen from a compound.
• Thermite Reaction: Aluminum reducing iron oxide to iron, generating a lot of heat; used in joining railway tracks.
• Electrolytic Reduction: Extracting highly reactive elements from molten salts.
• Electrolytic Refining of Copper: Impure copper (anode) and pure copper (cathode) in a copper sulfate solution resulting in pure copper on cathode, and anode mud.

Important Concepts and Processes

• Roasting: Heating ore (typically sulfides) in the presence of oxygen, producing sulfur dioxide.
• Calcination: Heating ore (typically carbonates) in the absence of oxygen, producing carbon dioxide.

Corrosion

• Corrosion: Metal reactions with the environment forming new compounds, changing properties.
• Examples:
  • Silver reacting with sulfur compounds to form black silver sulfide.
  • Copper reacting with carbon dioxide and water to form green copper carbonate.
  • Iron reacting with oxygen and water to form brown iron oxide (rust).

Alloys

• Alloys: Homogeneous mixtures of two or more metals, or a metal and a non-metal.
• Alloy Purposes: To improve the properties of metals (strength, hardness, corrosion resistance).
• Examples:
  • Steel (iron, chromium, nickel)
  • Brass (copper, zinc)
  • Solder (lead, tin)

Galvanization

• Galvanization: Coating iron or steel with zinc.
• Zinc's higher reactivity protects iron from corrosion; zinc acts as a sacrificial anode.