powerpoint metals and non metals

 PowerPoint presentation of  metals and nonmetals

name of the chapter: Metals and nonmetals 
Content Provider: FIITJEE
Lecturer from FIITJEE

an intro that just known to us (recall):

• Metals are described as chemical elements that readily lose valence electrons to form positive ions (cations).
  Examples: Aluminium, copper, iron, tin, gold.
• Around 90 of the total 118 elements are metals.

To know more about Metals, visit

Physical Properties

Physical Properties of Nonmetals

• Occur as solids, liquids, and gases at room temperature
• Brittle
• Non-malleable
• Non-ductile
• Non-sonorous
• Bad conductors of heat and electricity

Exceptions in Physical Properties

•  Alkali metals (Na, K, Li) can be cut using a knife.
• Mercury is a liquid metal.
• Lead and mercury are poor conductors of heat.
• Mercury expands significantly for the slightest change in temperature.
• Gallium and cesium have a very low melting point
• Iodine is non-metal but it has luster.
• Graphite conducts electricity.
• Diamond conducts heat and has a very high melting point.

Physical Properties of Metals

● Hard and have a high tensile strength
● Solids at room temperature, except mercury, which is liquid at room temperature.
● Sonorous
● Good conductors of heat and electricity
● Malleable, i.e., can be beaten into thin sheets
● Ductile, i.e., can be drawn into thin wires
● High melting and boiling points (except Cesium (Cs) and Gallium (Ga))
● Dense, (except alkali metals). Osmium – highest density and lithium – least density
● Lustrous
● Silver-grey in color, (except gold and copper)

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INTRODUCTION

Classification      of elements based on their physical and chemical  properties :

Ø  Metals ( eg: gold,silver,copper,potassium,sodium,aluminium      etc.,)

Ø  Non metals (eg:carbon,chlorine,phosphorus,oxygen,bromine,etc..,)

Ø  Metalloids - Exhibit properties   of both metals and non metals  (eg: silicon, germanium,boron,arsenic,antimony etc.,)

Total number of elements = 118  Naturally occuring          =             92

 

Physical Properties

Metals:

·         Generally solids at room temp,

Exception:           Gallium and Mercury

are liquids

* They are lustrous (shine)

* Metals are malleable (beaten into sheets)  GOLD is the most malleable metal

* Metals are ductile( drawn into wires

* Metals are hard

Exception: Sodium, Potassium,  Caesium, Lead

·         High M.P and B.P

·         Exception: Sodium, Potassium,  Lithium

·         Metals are good conductors of heat  and electricity

·         Silver is the best conductor of heat  and electricity followed by Cu, Au, Al

·         Exception: Lead and Mercury are

·         poor conductors of heat

 

 

Non-Metals:

* Exist as solids, liquids, and gases at  room temperature

* Bromine is a liquid nonmetal

* Non - lustrous

Exception: Iodine, Diamond

Graphite

* They are non-malleable

* non-ductile

* Nonmetals are generally soft and  some are brittle (they break on  heating)

Exception: Diamond is the  hardest substance

·         Low M.P and B.P

Exception: Carbon

 

Bad conductors of heat and electricity

Exception: Graphite is a good  conductor of electricity

 

AMPHOTERIC OXIDES

•                       Such metal oxides which react with both acids as well as bases to  produce salts and water are known as amphoteric oxides.

•       Aluminum oxide reacts in the following manner with acids and bases –

(BASE) Al₂O₃ + 6HCl → 2AlCl₃ + 3H₂O

(ACID)Al₂O₃            + 2NaOH → 2NaAlO₂ (Sodium aluminate)+ H₂O

Zinc and aluminum oxides are examples of amphoteric oxides

 

REACTION WITH OXYGEN ( NON-METALS)

•       When non-metals react with the oxygen they form their respective  oxides and by adding a small amount of water, the solution becomes acidic.

•       Eg: S +O2 → SO₂ ;             SO₂ + H₂O → H₂SO₃

 

 

 

REACTION WITH WATER (METALS)

 

•       Metal + Water → Metal oxide + Hydrogen

•       Metal oxide + Water → Metal hydroxide

•       Metals like potassium and sodium react violently with cold water. In the case of sodium and potassium, the reaction is so violent and exothermic that the evolved hydrogen immediately catches fire.

•       2K(s)      + 2H₂O(l) → 2KOH(aq)   +             H₂(g) + heat energy

•       2Na(s) + 2H ₂O(l) → 2NaOH(aq) + H₂(g) + heat energy

 

•       The reaction of calcium with water is less violent. The heat evolved is not sufficient for the hydrogen to catch fire.

Ca(s) + 2H₂O(l) → Ca(OH)₂(aq) + H₂(g)

•       Magnesium does not react with cold water.

It reacts vigorously with hot water to form magnesium hydroxide and hydrogen.

•       Metals like aluminum, iron, and zinc do not react either with cold or hot water. But they react with steam to form metal oxide and hydrogen. 2Al(s) + 3H2O(g) → Al2O3(s) + 3H2(g)

•       3Fe(s) + 4H2O(g) → Fe3O4(s) + 4H2(g)

•       Metals such as lead, copper, silver, and gold do not react with water at all.

 

REACTION WITH WATER (NON-METALS)

•       Nonmetals do not react with water.

•       Some non-metals like phosphorus is kept in water, so that its contact from the air can be avoided.

 

 

REACTION WITH ACIDS (METALS)

Metal + Dilute acid → Salt + Hydrogen

Eg: 2Al  +             6HCL→2AlCl₃ +3H₂

Fe           +             HCl → FeCl₂  +    H₂

•       Copper does not react with dil.HCl but reacts with conc. sulphuric and nitric acid.

•       Hydrogen gas is not evolved when a metal reacts with nitric acid  because HNO₃ is a strong oxidizing agent.

•       It oxidizes the H₂ produced to water and itself gets reduced to any of  the nitrogen oxides (N₂O, NO, NO₂).

•                       But magnesium (Mg) and manganese (Mn) react with very dilute  HNO₃ to evolve Hydrogen gas.

REACTION WITH ACIDS (NON-METALS)

 

•       Nonmetals do not react with acids, although sulfur reacts with hot concentrated nitric acid.

S+ 4HNO₃→SO₂ + 4NO₂ +2H₂O

•       METAL REPLACES METAL: Reactive metals can displace less reactive  metals from their compounds in solution or molten form.

Metal A + Salt solution of B → Salt solution of A + Metal B

Fe+CuSO₄→ FeSO₄+ Cu  Mg+CuSO₄ →MgSO₄+Cu

 

Nobel Metals

Metals that have very less tendency to react, that resisted chemical action, do not corrode, and can be found in a free state in nature are known as noble metals. eg: gold,silver,platinum          etc.,

Gold dissolves  in aqua Regia        (A mixture of conc.HNO3 and conc HCL in  the ratio 1:3 by volume)

 

USES OF METALS

•       Iron is the most commonly used metal, for the construction of

ships,buildings, automobiles and railway bridges, etc

is used for making jewelry, wires, and coins and in dentistry

•       Silver is used for making wires, utensils, statues, alloys, good reflecting

property of silver is also used in making mirrors

•       Tin is used for tinning food cans and alloys

•       Lead is used for making batteries and alloys

•       Zinc is used in the prevention of rusting, making alloys, and in dry cells

•       Mercury is used in making amalgams (an alloy of mercury with another metal,

especially one used for dental fillings) and in thermometers

•       Cu and Al is used in making wires, Al in food packing and in airplane parts

is used as the filament in incandescent light bulbs because it has the

highest melting point

Corrosion

•       Corrosion is an oxidation reaction with atmospheric oxygen in the presence of water on the surface of a metal.

•                       During corrosion, metals get converted to oxides, hydroxides, sulfides,  etc.

•       The corrosion of iron is called rusting

Fe           + O₂           → Fe₂O₃  (Rust which is brown in color)   + H₂O

•       Corrosion of copper: Copper reacts with moisture, carbon dioxide and  oxygen in the air and slowly loses its shiny brown surface and gains a  green coat. This green substance is copper carbonate.

Cu+ CO₂+ H₂O+ O₂ → CuCO₃.Cu(OH)₂

•       Tarnishing of silver: Silver reacts with sulfur (generally H₂S) in the atmosphere and the information of silver sulfide which is black in color.

Ag+H₂S→ Ag₂S

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