10th SCIENCE CHEMISTRY METALS AND NON METALS1st Blog

NOTES PREPARED BY 

ASHAQ HUSSAIN BHAT

 TEACHER SCHOOL 

EDUCATION DEPARTMENT

 JAMMU AND KASHMIR

Some Important  points to Remember

Metals Elements that are mostly solids, have bright lustre, high densities and are hard, good conductors of heat and electricity. They have tendency to lose one or more electrons , Zine, Sodium, Calcium, Aluminium

Non-Metals These elements exist in all the three states. They have no lustre. enerally low densities and are poor conductors of heat and electricity. They have tendency to gain one or more electrons eg,Nitrogen, Oxygen, Sulphur, lodine.Bromino etc

Metalloid The elements that show the properties of both metals and non metals.Arsenic,Antimony, Silicon Germanium. Tellurium etc.

Activity Series of Metals It is a series in which the various metals have been arrange in decreasing order of their reactivity. A part of this series is shown as below:-

K>Na>Ca>Mg>Al>Zn>Fe>Pb>Cu>Hg> Ag>Au >Pt

Mineral: The elementary state or the compounds in the form of which the metals occur in nature are called minerals 

Ore The mineral ore  from which the metal can be extracted conveniently and economically is called an ore.

GaugueOr Matrix. These are the earthy impurities like sand, lime stone, rocks etc. associated with minerals or Ores.

Metallurgy. The process of extracting and refining of metals is known as metallurgy

Roasting: The process of heating of Ore strongly in presence of air to get metal oxide is known as Roasting,

Calcination - The process of heating of carbonate ores to convert them into their corresponding oxides in absence of air, is known as calcination.

Smelting: - The process of reduction of metal oxides by heating them with coke is called smelting

Aluminothermy:- The process of reduction of metal oxides by heating them in presence of Aluminiumis called aluminothermy.

Refining of Metals:- The process of purifying the impure (crude) metals is called refining of the metals.

Corrosion. It is the Slow eating up (decay) of metals by the action of air and moisture on their surfaces.

Rusting:- Corrosion of iron is called rusting chemically rust is hydrated ferrio oxide (Fe 3 0⁴)

Alloy:- It is a homogeneous mixture of two or more metals or metals and non-metals.

 CLASSIFICATION OF ELEMENTS INTO

METALS, NON-METALS AND METALLOIDS

More than 114 different elements have been discovered so far. Many of them are found to occur in nature whereas some of them have been made by artificially and are called synthetic elements Based on their properties, they have been mainly classified into two categories Called metals and non metals. 

Metals are defined as those elements which possess lustre when freshly cut and are malleable and ductile and good conductor of heat and electricity. They may also be defined as those elements which lose electrons and form positive ions, i.e., they are electropositive elements (eg, Na —— Na+ + e-). 

A few examples are given below 

Sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), barium (Ba), aluminium (Al), copper (Cu), silver (Ag), gold (Au), platinum (Pt), nickel (Ni), chromium (Cr), iron (Fe), etc.

Non-metals are defined as those elements which do not possess lustre and are neither good conductor of heat and electricity nor malleable and ductile but are brittle. They may also be defined as those elements which may gain electrons and form negative ions, i.e., they are electronegative elements (e.g, Cl + e- Cl-). A few examples are given below: 

Hydrogen (H), oxygen (O), nitrogen (N), chlorine(CI), bromine (Br), sulphur (S), phosphorus (P), carbon (C), etc.

Metalloids

Besides metals and non metals, there is a third category of elements which show properties of both metals and non-metals. These elements are called metalloids. Their examples are given below

Silicon (Si), germanium (Ge), arsenic (As), antinomy (Sb) and tellurium (Te), 

The majority of the elements (about 80%) are metals. There are only 22 non-metals and very few are metalloids.

Importance of metals in our lives

 Metals are important in our daily lives in infollowing ways

(a) they are used to make almost all the parts of machines.

(b) , copper and aluminium metals are used to make wires which Carry electric current.

(c) silver and gold merals are used to make jewellery

(d) The aluminium are used in packing of medicines , Cigrates and food materials 

(e) The liquid metal mercurry  (Hg) is used to make thermometes.

(f) Copper , Gold and almunium metals are used to make household utensils and factory equipments.

(g) Zirconium metals is used in making bullet proof alloy  steels

Importance of non metals in our lives

 The most important uses of non metals are

(1) Hydrogen is used in the manufacture of ammonia

(2) Hydrogen is used in the hydrogenation of vegetable oils to make ghee.

(3) Liquid Hydrogen is used as rocket fuel 

(4 )Carbon in the form of graphite is used for electrodes of electrolytic and dry cells

(5)'Nitrogen' is used in the manufacture of fertilizers, Nictric acid and ammonia

(6)Nitrogen' being inert is  used to preserve food materials.

(7) sulphue is used as fungicide and in making of  Gunpowder

(8) Sulphue is used in the manufacture of Sulphuric  acid.

 Give physical and chemical properties of metals.

Physical Properties of metals:-

The general physical properties of metals are stated as follows:-

1. Metals in the pure state possess lustre i.e. shining surface.
2. Metals are generally hard. The hardness varies from metal to metal e.g. Iron, Copper,Aluminium. Lead are hard metals. They can't be cut with a knife. However, Lithium, Sodium and Potassium are sofi metals. They can be cut even with a knife.
3. Metals are malleable i.e. they can be beaten into thin sheets.e.g. Iron, Copper, Aluminium etc
4. Metals are ductile in nature i.e. they can be drawn into wires. e.g. 1 gram of gold can be drawn into a wire of about 2km length.
5. Metals are good conductors of heat and possess high melting point. silver is the best conductor of heat and copper is the second best followed by aluminium. However, lead is the poorest conductor of heat'
6. Metals are good conductors of electricity, Silver is the best conductor of electricity where as mercury is very poor conductor of electricity.
7. Metals are sonorous i.e. they produce sound on striking hard surfaces.
8. Metals generally have high density. Exception is Lithium, Sodium, and Potassium which have low densities.
9. Metals have high tensile strength i.e. they possess load bearing capacity.
10. All metals are solids except mercury which is a liquid.

Chemical properties of Metals:-

Some of the chemical properties of metals are summarized as follows:-

1. Reaction of metals with oxygen:-

Metals react with oxygen to form their respective oxides. e.g. 

 :-Sodium reacts with oxygen at room temp. 

4Na + O²---------------->2Na2O

:- Magnesium reacts with oxygen on heating.

                           Heating

2Mg:+ 02 ------------------>2MgO

          

:-Zinc reacts with oxygen on strong heating.

                       Strong

2Zn +02------->2Zno

             Heating

• (a)Basie Amphoterie nature of oxides. 

Most of the Metal oxides are basic in nature, Sodium rects with oxygen at room temperature to form sodium oxide which is basie in nature

4 Na +O2----------->2Na2O

Similarly Magnesium reacts with oxygen op on heating to form magnesium oxide which is also basic in nature.

                          Heating

2Mg + O₂---------->2Mgo

However, some metal oxides erg. aluminium oxide (Al²0³) and Zinc oxide (ZnO) show basic as well as acidic character. Such metal oxides are called amphoteric oxides

4 Al +302-------------->2 Al2O3

2 Zn +02---------------->2 Zno

• (b) Solubility in water:-

 Most of the metal oxides are insoluble in water. But some metal oxides dissolve in water to form alkali.eg. 

Na 0+H2O----------->2Na OH

KO + H20-------------------->2KOH

• 2 Reaction of Metals with water:-

A number of metals react with water to form a hydroxide or an oxide along with the evolution of hydrogen gas. However, the vigor of reactivity of different metals is different towards water. Some metals such as sodium and potassium react with water at room temp.

2 Na + 2H 0------------>2NaOH + H2

2K +2H2O---------------->2KOH + H2

Some metals such as magnesium reacts with water on heating

Mg+2H2O------------->Mg (OH) + H2

Similarly some other metals such as aluminium and iron react with steam

.                   steam

2A+3H2O----------------->Al2O3 + 3H2

                   (Steam)

3Fe+4H2O------------------> Fe³ O⁴ + 4H2

• 3 Reaction of Metals with dilute acids:-

Metals displace H² gas from dilute acids. However, less reactive metals like Cu, Ag and Au do not displace Hydrogen gas when they are  treated with dilute acids.e.g. 

(a) Sodium reacts violently with dil. HCI.

2Na + 2HCI----------->2 NaCl + H2

(b) Magnesium reacts quite rapidly with dil. HCI.

Mg + 2HCl ------------>MgCl2 + H2

(C) . Zinc reacts less rapidly than that of Mg with HCI

Zn + 2HCI------------>Zncl2 + H₂

(d) . Iron reacts slowly with dil - HCI

Fe + 2HCl----------------> FeCl2 + H2,

(e) Copper does not react with dil HCI or dil 

H2 SO4

Cu + HCI------------------>NO reaction

• (4)Reaction of metals with chlorine

Metals react with chlorine to form metal chlorides. Reactive metals like sodium,

potassium, calcium and magnesium combine with chlorine even at room temp.

2 Na+Cl2--------------->2Nacl

Ca + Cl2---------------->CaCl2

However, less reactive metals like zinc, iron, aluminium and copper react with

chlorinc. on heating, eg,

                                  Heat

  Zn +Cl2------------>ZnCl2

                      Heat

2Fe+3 Cl2--------------->2FeCl3

                         Heat

2Al+3Cl2--------------------->2AlCl3

• 5 Reaction of metals with hydrogen:-

Metals generally do not react with hydrogen. Only highly reactive metals like Na, K ,Ca and Mg combine with hydrogen to firm compounds called metal hydrides. e.g.

2 Na+H2----Heat------>2NaH

Ca +H2-----Heat------->CaH2

• 6 Reaction of metals with solutions of other metal salts:-

All metals are not equally reactive. The more reactive metals can displace less reactive metals from their compounds in solution. e.g. Iron can displace copper from copper sulphate solution.

Fe+   +  CuSO4------------->FeSO4 + Cu.

Similarly, copper can displace silver from silver nitrate solutions

Cu +2Ag NO3---------->Cu(NO3)2 + 2Ag.

• 7. Reducing behaviour:-

As metals can lose electrons, therefore, they act as reducing agents.e.g, sodium metal reduces chlorine to chloride ion. As follow:-

2 Na+Cl2----------->2 Nacl

        Oxidation

Na-------------->Na +e–

        Reduction

(CI-------------CI

Na+      +Cl– -------------->Nacl.

Give their general physical and chemical properties.

Physical properties of non-metals:-

Some of the general physical properties of non-metals are as follow:

(1) Non-metals do not possess any' lustre except iodine which is non-metallic solid but has lustre.

(2) They are soft and brittle i.e. they break into pieces when hammered. The only exception is diamond, an allotropic form of carbon which is a non-metal but is the hardest substance known.

(3) They are neither malleable nor ductile.

(4) They are generally bad conductors of heat and electricity, except graphite which is an allotropic form of carbon and is a good conductor of electricity.

(5) They are non-sonoraus i.e. they do not produce any sound when hit with hard object.

(6) They have generally low melting, and boiling point except boron, diamond and graphite which are non-metals but have high melting point.

(7) They have low densities i.e. they are light elements.

 (8) They have low tensile strength i.e. they are easily broken.

(9) They may be solids, liquids or gases at room temperature. e.g. Carbon, Sulphur, phosphorus are solids and iodine is a liquid, while as  hydrogen, oxygen, nitrogen and chlorine are gaseous non-metals.

Chemical properties of non-metals:-

Some important chemical properties (reactions) of non-metals are discussed below.

(1) Reaction with oxygen :- Non-metals when heated with oxygen form their respective

oxides. These oxides may be either acidic or neutral. They never form basic oxides.

e.g

C+0₂------------->CO2

                        (Acidic oxide)

CO2 +H2O---------->H2CO3

                                (Carbonic acid)

S+02------------------->SO2

                                  (Acidic oxide)

SO2 + H2O-------------->H2SO3

                                (Sulphurous acid)

2C + O2-------------------->2CO

                               (Neutral oxide)

N2 + O2,------------------>2NO

                                 (Neutral oxide)

(2)Reaction with water:- Non-metals generally do not react with water. This is non-metals can't reduce the hydrogen (H) ions of water to H2 gas.

(3) Reaction with dilute acids:- Non-metals do not react with dilute acids. It is non-metals them selves are acceptors of electrons and therefore do not give to reduce the hydrogen (H)ions of an acid to hydrogen gas

(4)Reaction with chlorine:- Non-nfetals react with chlorine to form chlorides. These non-metal chlorides are covalent chlorides and non-electrolytes, e.g.

H2 + Cl2----------2HCI

              (Covalent Chloride)

P4 +6Cl2-----------------4PCI3

               (Covalent Chloride)

(5) Reaction with hydrogen:-

Non-metals combine with hydrogen to form covalent hydrides. These hydrides are generally gases or liquids e.g.

8H2 +S8-----------8H2S

N2+ 3H2---------------2NH3

(6) Reaction with Salts:-

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

e.g

                       Heat

2NaBr+Cl2--------------2 NaCl + Br2

                      Heat

2KI+Cl2-------------------2KCI + I2

(7)Oxidizing Behavior:-

Non-metals have a strong tendency to accept electrons to form negative ions. Therefore, non-metals behave as oxidizing agents. e.g. the non-metal fluorine (F2) is the strongest oxidizing agent. It oxidizes water (H2O) to oxygen, sulphur to sulphurhexa fluoride etc.

2H20. + 2F2------------->4HF + O2

S8 + 24F2------------------->8SF6

 State some uses of metals:-

 Metals are used for a large number of purposes. Some of the uses of metals are given below-

1. Copper and aluminium metals are used to make wires to carry electric current.

2. Iron, Copper and Aluminium metals are used to make house-hold utensils and factory equipments.

3. Iron is used as a catalyst in the preparation of ammonia gas by Haber's process.

4. Zinc is used for galvanizing, iron to protect it from rusting.

5. Chromium and nicked metals are used for electroplating and in the manufacture of stainless steel

6. The aluminium foils are used in packaging the medicines, cigarettes and food materials.

7. silver and gold are used to make jewelery.

8. The liquid metal, mercury is used in making thermometers.

9. Zirconium metal is used in making bullet proof alloy steels.

Q.4 State some important uses of non-metals.

Hydrogen is used in the hydrogenation of vegetable oils to make vegetable ghee (or venaspati ghee.) Hydrogen is also used in the manufacture of ammonia. The later is used for the manufacture of fertilizers.

2. Carbon is one of the most important non- metal because life is based up on it. For example carbohydrates, proteins, oils and fats, vitamins, enzymes etc. which are all made up of carbon compounds. Carbon in form of graphite, is also used as electrodes in electrolytic cells and dry cells.

.3.Oxygen gas in air'imparts its use in different life processes and combustion processes

4. Nitrogen is used in the manufacture of ammonia, nitric acid and fertilizers. Some of the compounds of nitrogen, such as trinitrotoluene (TNT), nitroglycerine etc. are used as explosives.

5. Sulphur is present in many of the substances found in plants and animals. It is present in proteins, hair, Onion, garlic, wool etc. it is used in as a fungicide and in making gunpowder... 

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