Periodic Table

Metals

• Metals are substances which are electropositive in nature i.e., they have a tendency to lose electrons to complete their octet.
• Examples:

1. Sodium (Na) = 2,8,1
   Na –> Na⁺ + e^–
   
2. Magnesium (Mg) = 2,8,2
   Mg –> Mg⁺² + 2e^–

Non – Metals

• Non-metals are substances which are electronegative in nature i.e., they have a tendency to accept electrons.
• Example:

1. ₁₇Cl = 2,8,7
   Cl + e- –> Cl^– (2,8,8)
   
2. ₈O = 2,6
   O + 2e^– –> O^2- (2,8)

Physical Properties

METALS	NON-METALS
Metals are generally solid. Examples-  Iron, Gold and so on. Exception- Mercury, Gallium	Nonmetals exist in all three states of matter.
	Solid- Carbon, Phosphorous, Iodine
	Liquid- Bromine
	Gases- Chlorine, oxygen, nitrogen and so on.

Metals

Non – Metals

METALS	NON-METALS
Metals have lustre ( Ability to shine and reflect light surface) and can be polished. Except: Lead ( Have dull appearance)	Nonmetals are dull. Except: Iodine, Diamond and graphite.

METALS	NON-METALS
Metals are generally hard  Except: Mercury (Liquid), Gallium (Liquid in room temperature), Sodium, and Potassium are soft metals	Nonmetals are generally soft. Except: Diamond is one of the hardest known substance.

METALS	NON-METALS
Metals generally have a high melting point and boiling point. Except: Mercury	Nonmetals generally have low melting point and boiling point Except: Silicon, Boron ( Metalloids), Carbon ( Diamond).

METALS	NON-METALS
Metals have high density.      Except: Sodium and Potassium can be cut with knife.	Nonmetals have low density. Except: Diamond

METALS	NON-METALS
Ductility: The property which allows the metals to convert them into thin wires. Eg- The most ductile metal is gold. One gramme of gold may produce a wire with a length of around 2 kilometers.	Non metals are not ductile. Exception- Carbon fiber. It is used to make aircraft and spacecraft parts, racing car bodies, bicycle frames etc.

METALS	NON-METALS
Malleability: Malleability is the ability of a substance to be beaten into thin sheets. Eg- Gold, Aluminium. Exception- Sodium, Potassium, Mercury, Zinc	Nonmetals: are not malleable. We cannot make sheets with non-metals.

METALS	NON-METALS
Brittleness: Brittleness refers to a material’s inability to deform due to its atomic microstructure. On applying force something break. Metals are generally hard but not Brittle. Exception: Zinc is a brittle metal.	Solid nonmetals are generally Brittle. Examples- Graphite, coal Exception: Gases.

METALS	NON-METALS
Conduction of heat and electricity Metals are good conductors of heat and electricity. Exception – Tungsten wire	Conduction of heat and electricity  Nonmetals are bad conductor of heat and electricity Exception – Gas carbon, Gas fiber, Graphite

Types Of Ions

• Metals form positive charge ions called Cations.
  Metals have valence electrons = 1,2,3
• Example:
  1. ₁₁Na = 2,8,1
  Na –> Na⁺ + e^–
  
  2. ₂₀Ca = 2,8,8,2
  Ca –> Ca⁺² + 2e^–

• Whereas, Non-metals forms negative charge ions called Anions.
  Non-metals have valence electrons = 4,5,6,7
• Example:
  1. ₉F = 2,7
  F + e^– –> F^–
  
  2. ₁₇Cl = 2,8,7
  Cl + e^– –> Cl^–

Chemical Properties Of Metals

• Reaction with oxygen

• Not all metals react with the same level of reactivity.

Metal + Oxygen -> Metallic Oxide

(heat)

• 2Mg + O₂ —> 2MgO

(room temp)

• 4Na + O₂ ——> 2Na₂O

Reactivity Series of Metals

(From most reactive to least reactive)

Potassium (K)
Sodium (Na)
Calcium (Ca)
Magnesium (Mg)
Aluminium (Al)
Zinc (Zn)
Iron (Fe)
Lead (Pb)
Copper (Cu)
Silver (Ag)
Gold (Au)

Reactivity Level	Metals
Most Reactive	Potassium (K) Sodium (Na) Calcium (Ca)
Moderately Reactive	Magnesium (Mg) Aluminium (Al) Zinc (Zn) Iron (Fe) Lead (Pb)
Reference Element	Hydrogen (H)
Least Reactive	Copper (Cu) Mercury (Hg) Silver (Ag) Gold (Au)

Chemical properties of Non-metals

• Reaction with oxygen

Non-metal + Oxygen → Non-metallic Oxide

• Examples:

1. C + O₂ → CO₂
2. S + O₂ → SO₂
3. 2H₂ + O₂ → 2H₂O

• Reaction with Salt Solutions

A more reactive non-metal displaces a less reactive non-metal from its salt solution.

For Example:

2NaBr(aq) + Cl₂(g) –> NaCl(aq) + Br₂
(Less reactive) (More reactive)

• REACTION WITH ACID

Non-metals lack an excess of electrons to donate.

Hence, Non-metals do not generally react with acids because they are not easily capable of donating electrons to the hydrogen ions (H⁺) produced by the acids.

Chemical Properties of Metals

• NATURE OF OXIDE

Metallic Oxide

Metallic oxides are of two types:

1. Basic Oxides

Examples:

• Na₂O
• CaO
• MgO
  etc.

2. Amphoteric Oxides

Examples:

• ZnO
• PbO
• Al₂O₃

Non-metallic Oxides

Non-metallic oxides are of two types:

1. Acidic Oxides

Examples:

• CO₂
• SO₂
• P₂O₅

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2. Neutral Oxides

Examples:

• CO
• NO
• H₂O
  etc.

• REACTION WITH WATER

React with Cold Water

• Potassium (K)
• Sodium (Na)
• Calcium (Ca)

---

React with Hot Water or Steam

• Magnesium (Mg) → reacts with hot water and steam

---

React with Steam

• Aluminium (Al)
• Zinc (Zn)
• Iron (Fe)

---

No Reaction with Water or Steam

• Lead (Pb)
• Hydrogen (H)
• Copper (Cu)
• Mercury (Hg)
• Silver (Ag)
• Gold (Au)
• Platinum (Pt)

• Note:

Metal + H₂O (water) –> Metallic hydroxide + H₂(g)

Metal + H₂O(steam) –> Metallic oxide + H₂(g)

• REACTION WITH WATER

Non–metals do not react with water (or steam) to evolve hydrogen gas. This is because non-metals cannot give electrons to reduce the hydrogen ions of water into hydrogen gas.

• REACTION WITH ACID

Metal + Acid → Salt + Hydrogen gas
(Dilute acids; except nitric acid (HNO₃)

Examples:

1. Zn + 2HCl (dilute) –> ZnCl₂ (aq) + H₂ (g)
2. Zn + H₂SO₄ (dilute) –> ZnSO₄ + H₂(g)

• HNO₃ is a strong oxidizing agent.
  When it reacts with a metal, it oxidizes the hydrogen gas and forms water (H₂O).

• Exception:

Mg + HNO₃ –> Mg(NO₃)₂ + H₂

Mn + HNO₃ –> Mn(NO₃)₂ + H₂

• AQUA REGIA

Aqua – regia is a freshly prepared mixture of 1 part of concentrated nitric acid and 3 parts of concentrated hydrochloric acid.

HNO₃ + 3HCl –> NOCl + H₂O + [Cl] (This can dissolve Au & Pt metal also.)

Au + 3[Cl] –> AuCl₃

Pt + 4[Cl] –> PtCl₄

• Reaction with Solution of Other Metal

More reactive metal can displace less reactive metal from its salt’s solution.

1. Fe + CuSO₄ —-> FeSO₄ + Cu
   (Grey) (Blue) (Colorless) (Brown colour)

2. Al + FeSO₄ —> Al₂(SO₄)₃ + Fe

• Summary for chemical properties of metals

Elements	Reaction with oxygen	Reaction with water	Reaction with acids
1. K 2. Na 3. Ca	React with oxygen at ordinary temperature to form oxides.	K and Na react vigorously with cold water Ca reacts moderately with cold water.	K and Na react explosively with dilute acids to give hydrogen but Ca reacts less vigorously.
4. Mg 5. Al 6. Zn 7. Fe	Form oxides on heating, but Aluminium reacts with it at ordinary temperature.	Mg reacts with hot water or steam; others react with steam only to from oxide and hydrogen.	Mg, Al, Zn and Fe react moderately with acids to produce hydrogen.
8. Pb 9. Cu 10. Hg	From oxides on very strong heating	No reaction with hot water or steam.	Pb reacts with conc. HCL to give H_2,Cu and Hg do not react with dilute acids.
11. Ag 12. Au 13. Pt	Do not react with oxygen even on strong heating	No reaction with hot water or steam.	Do not react with dilute acids.

• How do metals and non-metals react

Everyone desires stability in their lives.

For atoms, stability means achieving inert gas configuration.

A Chemical bond may be defined as the force of attraction between any two atoms, in a molecule, to maintain stability.

Types Of Bonding

Ionic Bond – Formed between metals and non-metals.

Covalent Bond – Bond formed between non-metals.

Electrovalent (Or Ionic Bond)

The chemical bond formation in this is due to the electrostatic force of attraction between a cation and an anion. It is called an electrovalent  (or ionic) bond.

Example:

Lets take the example for NaCl,
Here, Na is the metal and Cl is the non-metal.

₁₁Na = 2,8,1 –> Na⁺= 2,8
₁₇Cl = 2,8,7 –> Cl^–= 2,8

[Na]⁺[Cl]^– (Strong Electrostatic force of attraction exists between Na⁺ & Cl^–)

Characteristics Of Ionic Compounds

• Physical state – They are generally crystalline solids because the force of attraction between the particles is more.

• They have a high melting point and boiling point.

• They are highly soluble in water because water molecule surrounds cation and anion. Also, Ionic compounds are insoluble in organic solvents for example – CCl₄, CS₂, C₆H₆, C₆H₅CH₃

• Note – Since water is a polar compound, hence ionic compounds are soluble in water.

• Their density is generally more than the density of water.

• In a fused state or in an aqueous solution, they are good conductors of electricity but in a solid state, they do not conduct electricity.

• Ques – Why solid NaCl does not conduct electricity but molten or aqueous conduct electricity?

• Ans – Solid NaCl does not conduct electricity because its ions are held tightly in a fixed position and cannot move to carry an electric current. However, when NaCl is melted or dissolved in water, its ions become free to move and can carry an electric current, making the solution conductive.

Why Ionic Compounds Are Stable

• The electrostatic force of attraction between opposite charges is much higher, it makes the ionic compounds stable.
• The strong ionic bond, regular crystal lattice structure, and high melting and boiling points all contribute to the stability of ionic compounds.

Redox Reaction

Oxidation and reduction occur simultaneously because the electrons lost by the reducing agent must be gained by the oxidizing agent.

Reducing agents are electron donors & Oxidizing agents are electron acceptors.

Metals are reducing agents       Non-metals are oxidizing agents

Oxidation Reaction	Reduction Reaction
1. Gain of oxygen	1. Loss of oxygen
2. Loss of hydrogen	2. Gain of hydrogen
3. Loss of electrons (e⁻)	3. Gain of electrons (e⁻)
4. Increase in oxidation number (O.N / charge)	4. Decrease in oxidation number (O.N / charge)

Example:

2K⁰+Cl₂⁰​→2K⁺Cl⁻

Oxidation:

Potassium (K) loses one electron to form K⁺.
Oxidation number of potassium increases from 0 to +1.
Hence, oxidation occurs.

Reduction:

Chlorine (Cl₂) gains electrons to form Cl⁻.
Oxidation number of chlorine decreases from 0 to −1.
Hence, reduction occurs.

Reducing Agent (R.A.):

Potassium is the reducing agent because it donates electrons to chlorine.

Oxidizing Agent (O.A.):

Chlorine is the oxidizing agent because it accepts electrons from potassium.

COVALENT BOND

• The Chemical bond formed by the mutual sharing of one or more pairs of electrons is called a covalent (molecular) bond and the compound formed due to this bond is called a covalent compound.

• TYPES OF COVALENT BOND

Single Covalent Bond

Double Covalent Bond

Triple Covalent Bond

Type of Covalent Bond	Electrons Shared	Examples

Single Covalent Bond

Sharing of 1 e⁻ pair

H–Cl, H–F

Double Covalent Bond

Sharing of 2 e⁻ pairs

O=O, H₂C=CH₂

Triple Covalent Bond

Sharing of 3 e⁻ pairs

N≡N, HC≡CH

Characteristics of covalent bond

• They are generally gaseous or volatile liquids or soft solids because they have a weak intermolecular force of attraction.
• Covalent compounds are volatile compounds with low melting and boiling point.

• Insoluble in water, but soluble in organic solvents.
• Lower density than water.

• Poor conductors of electricity because they lack ions and only contain molecule.

Occurrence of metals

• The earth’s crust is the major source of metals.
• Most of the metals are quite reactive and hence they do not occur as free elements in nature.
• Only a few less reactive metals (like copper, silver, gold and platinum are found in the ‘free state’ as metals.
• Copper and silver metals occur in free state (native state) as well as in the combined state (in the form of compounds).

Minerals and ores

• Minerals refer to naturally occurring elements or compounds found in the Earth’s crust.

• Ores, on the other hand, are minerals that can be extracted conveniently and profitably for their metal content.

EXTRACTION OF METALS

EXTRACTION OF METALS – CONCENTRATION

• The process of removing gangue, the rocky impurities like SiO₂ present in an ore is called as the concentration of an ore.

• The unwanted impurities like sand, rocky material, earth particles, animal decay, etc, present in an ore are called gangue.

• The concentration of crushed ore is done mainly by the following methods –

1. Gravity Separation or Hydraulic washing

2. Froth Floatation

3. Magnetic Separation

4. Chemical Method or Leaching

Minerals and ores

• The three major steps involved in the extraction of a metal from its ore are:
  1. Concentration of ore (or Enrichment of ore).
  2. Conversion of concentrated ore into metal.
  3. Refining (purification) of impure metal.

EXTRACTION OF METALS – CONCENTRATION

• Gravity Separation or Hydraulic washing – The difference in the densities of the ore and the gangue is the main criterion.

• Froth Floatation – Either ore or impurities one should have hydrophobic or hydrophilic in nature.

• Magnetic Separation – Magnetic properties of metals.

• Chemical Method or Leaching – Impurities are removed by filtrations.

EXTRACTION OF METALS – ORE TO OXIDE CONVERSION

• Concentrated ore is converted to its oxide because oxides are easier to reduce into metals.
• Two methods are used to convert the ore into its oxide –

1. Roasting – Burning ores in excess supply of oxygen.

ZnS + O₂ —-> ZnO + SO₂

2. Calcination – Burning ores in limited supply of oxygen.

(heat)
CaCO₃ ———> CaO + CO₂

Extraction of metals: Reducing oxides to metals

Note: The selection of reducing agents depends on the relative position of the metal in the activity series.

K Zn Hg

Na Fe Ag

Ca Pb Au

Mg Cu Pt

REFINING OF THE METAL

• Electro refining – In electrolytic refining, the anode is made from impure metal and the cathode is that of pure metal. 
  When electricity is passed, the pure metal in the anode goes and deposits over the pure metal at the cathode, and the impurities left behind settle down in the anode. This is called anode mud.

Corrosion

• When a metal is attacked by substances around it such as moisture, acids, etc., it is said to corrode and this process is called corrosion.
  
  Examples:

1. Reddish brown coating on iron-

Fe + H₂O + O₂ —> Fe₂O₃.xH₂O

2. Black coating on silver – Silver reacts with sulphur and sulphur compounds
in the air to give silver sulphide (Ag₂S) which is black.

Ag + H₂S —> Ag₂S (Black) + H₂

3. Bluish-Green coating on copper –

Cu + CO₂ + H₂O + O₂ —-> Cu(OH)₂ + CuCO₃ (Green)

HOW TO PREVENT CORROSION

• Corrosion causes damage to car bodies, bridges, iron railings, ships and to all objects made of metals, specially those of iron.
• Corrosion of iron is a serious problem.

• Every year an enormous amount of money is spent to replace damaged iron.

• HOW TO AVOID CORROSION

1. Painting

2. Greasing

3. Galvanization

4. Electroplating