Metallurgy and Non-metals

• Elements are divided into metals and non-metals
• Metals can readily lose electrons to form positive ions, or cations
• Non-metals readily gain electrons to form negative ions, or anions
• Metals bond with metallic and non-metallic atoms
• Metals are electropositive elements that lose or donate electrons.
• Most elements are metals (118 known)
• Major metals are Aluminum, Iron, Calcium, Sodium, Potassium and Magnesium

Metals

• Metals: occurance, physical properties, reactivity, chemical properties & uses
• Non-metals: occurance, physical properties, reactivity, chemical properties & uses
• Comparative study of Metals and Non-metals
• Interactions in Metals and Non-metals
• Chemical Bond
• Causes of Chemical Bond Formation, Types of Chemical Bonds
• Ionic Bonds: example, nature, structure, characteristics
• Metals in Nature: ores
• Metallurgy : Extraction of Metals using reactivity
• Alloys: preparation, properties

Occurrence of Metals

• Metals are mainly found in the earth's crust in free and combined states
• Reactive metals form compounds, such as carbonates, sulphates, and oxides eg Copper
• Less reactive metals exist in elemental form, like Gold (Au), Silver (Ag), Plantinum (Pt)

Physical Properties of Metals

• Hard solids at room temperature with exceptions of Sodium (Na) and Potassium (K)
• Mercury is a liquid metal
• High Melting and Boiling Points with some exceptions of Na and K
• Beryllium has a melting point of 1287°C and boiling point of 2472°C
• Metals have shiny, reflecting surfaces
• Gold (Au) has a shiny surface
• Malleability: Metals can be beaten into thin sheets
• Aluminum, Gold, Silver can be beaten into thin sheets like aluminum foils, gold foils and silver foils
• Ductility: Metals can be drawn into chains or wires
• Gold (Au) and Silver (Ag) can be made into chains and cable wires are made of copper
• Thermal Conductivity: Metals transfer heat efficiently
• Silver and copper are the best conductors of heat
• Electrical Conductivity: Metals conduct electricity due to free electrons
• Silver, Copper, Iron etc all conduct electricity
• Sonority: Metals produce a ringing sound when struck
• Strength: Metals are strong and can hold heavy weights
• Iron is a strong metal
• Density: Typically have high densities and are heavy substances
• Iron and manganese have high densities of i.e., 7.8 g/cm³ and 7.4 g/cm³ respectively
• Metals are usually silvery/grey or golden yellow color

Activity Series of Metals

• Metals are arranged by reactivity
• The most reactive metal is potassium (K) and the least reactive is Platinum (Pt)
• Electropositive character decreases down the series
• Metals above hydrogen can displace hydrogen from water and dilute acids
• Metals below hydrogen cannot displace hydrogen from water and dilute acids
• A high placed metal can displace a low placed metal from its salt solution
• Oxides of K, Na, Ca, Mg, and Al cannot be reduced by H2, C or CO
• Oxides (below aluminum) reduce by H2, C or CO
• Oxides of very less reactive metals like Hg, Au can be reduced by heating

Chemical Properties of Metals

• Metals are electropositive, losing electrons easily to form cations
• Sodium → Sodium⁺ + e
• Magnesium → Magnesium²⁺ + 2e⁻
• Electropositive nature allows metals to form compounds.

Reaction of Metals with Oxygen

• Metals combine with oxygen to form metal oxides.
• Metal + oxygen → metal oxide
• Metal oxides are basic and form bases when dissolved in water, turning red litmus blue.
• Metal oxide + water → base

Reaction of Metals with Water

• Metals react with water to produce hydrogen gas, forming metal oxides or hydroxides
• Metal + water → metal hydroxide + hydrogen gas
• Metal + water → metal oxide + hydrogen gas
• Potassium reacts vigorously with cold water to form potassium hydroxide and hydrogen gas
• Metals placed above hydrogen in activity series displace hydrogen from acids
• Strong acids like HCl, H2SO4 readily lose hydrogen, faster than weak acids

Reaction of Metals with Salt Solutions Containing Less Reactive Metals

• A more reactive metal displaces a less reactive metal from its salt solution.
• Displacement reaction: M₁ + Salt solution of M₂ → M₂ + Salt solution of M₁

Uses of metals

• Metals are essential in bio-processes, daily goods, machines, accessories, health equipment, space projects, and nuclear fuel.
• Iron (Fe) is in haemoglobin
• Copper (Cu) and Aluminum (Al) are used in wires and cables
• Gold (Au), Silver (Ag) and Platinum (Pt) are used for jewellery
• Mercury (Hg) thermometers

Non-Metals

• Readily gain electrons to form negative ions (anions) and covalent bonds
• 18 known non-metals: Carbon (C), Nitrogen (N), Oxygen (O), Phosphorus (P), Sulphur (S), Selenium (Se)
• Can be found in all 3 states
• Low boiling and melting Points

Physical Properties of Non-metals

• Non-metals are found in all three states of matter (solid, liquid and gas)
• Most non-metals have low boiling and melting points
• Generally soft, with diamond as an exception which is very hard
• Non-lustrous and brittle rather than ductile
• Bad thermal and electrical conductors with the exception of Graphite
• Non-sonorous
• Have low densities
• Show different colours (Sulphur is Yellow, Phosphorus is white, red, or black)

Occurrence of Main Non-Metals

• Carbon: as carbon dioxide and carbonates in rocks
• Oxygen: as oxides and in carbonates
• Hydrogen: as water and hydrides
• Nitrogen: as nitrites and nitrates in soil
• Sulphur: as sulphides and sulphates
• Phosphorus: as phosphates in rocks
• Silicon: as silica or silicates in sand, quartz, mica, asbestos, and clay

Reaction of Non- metals with Oxygen

• Non-metals form non-metallic oxides
• Non-metal + oxygen → non-metallic oxide
• React with oxygen to form acidic oxides that turns blue litmus paper red
• Carbon and oxygen react to form acidic carbon dioxide that dissolves in water to make carbonic acid
• Nonmetals cannot react with dilute acids
• A more reactive non-metal displaces a less reactive one from its salt solution

Uses of Non-Metals

• Carbon dioxide and oxygen are necessary for life and photosynthesis
• Sulphur is used as a fungicide and chlorine is a disinfectant.
• Hydrogen is used as a fuel.

Differences Between Metals and Non-Metals

• Metals are malleable & ductile where are Nonmetals are non-malleable & non-ductile
• Metals form cations and Nonmetals form anions
• Metals form basic oxides and Nonmetals form acidic oxides

Interactions Between Metals and Non-Metals

• When metals react with non-metals, they form ionic compounds
• When non-metals react together they form covalent molecules.
• Metallic and non-metallic atoms combine due to chemical bond.
• The force that holds two atoms together is a chemical bond

Chemical Bond Formation

• Atoms combine to attain stability by forming molecules.
• Attaining inert gas electronic structure (8 electrons in valence shell)
• Types of bonds: ionic, covalent, and coordinate

Electrolytic Reduction

• Metals like Na, K, Mg, Ca, Al, etc. are reduced by electrolysis of their oxides, hydroxides or chlorides in a molten state.
• For example, sodium is obtained from molten NaCl.

Refining of Metal

• Purification occurs after reduction
• Can be associated with impurities such as uncharged ore and other compounds of metals
• Impurities like silicon, carbon, phosphorou, Slag, flux etc should be removed
• Process: Dissociation of electrolyte (CuSO4 solution) and reaction at the cathode

Questions covering metal extraction techniques like thermite process and electrolytic reduction. Properties of non-metals including conductivity, physical states, and allotropes are also covered.