Notes C - 2, Metals and non metals




Physical Properties of Metal

-   Metals are Lustre means they have shiny surface
-   Metals are generally hard. Except – Sodium, Lithium and Potassium
-   Metals are found in solid state. Except – Mercury
-   Metals are Malleable it means metals can be beaten into thin sheets
                Gold  and silver are most malleable metals
-   Metals are ductile it means metals can be drawn into thin wires.
-   Metals are good conductor of heat and electricity
                Silver and Copper are best conductor of Heat and Electricity
-   Metals have high density that’s why metals melting point is high.
                Except -  Sodium and Potassium
-   Metals are Sonorous means metals produce sound when strike by a hard surface
-   Metal oxides are basic in nature.


Physical Properties of Non- Metal

-   Non- Metals are not Lustre means they do not have shiny surface
                 Except -  Iodine
-   Non- Metals are generally soft.
Except –  Except diamond ( it is a form of carbon)
-   Non- Metals are exist in solid or gaseous  state.
 Except – Bromine (liquid)
-   Non- Metals are not Malleable it means Non-  metals can’t  be beaten into thin sheets
-   Non- Metals are non ductile it means Non- metals can’t be drawn into thin wires.
-   Non- Metals are poor conductor of heat and electricity
-   Non- Metals have high density that’s why Non- metals melting point is very low. 
-   Non- Metals are not Sonorous means Non- metals do not produce any sound when strike by a hard surface
-   Non- Metal oxides are acidic in nature.


Chemical Properties of Metals

(A) Reaction with Air – Metal combine with oxygen to form metal oxide.
                Metal   +   Oxygen →  Metal Oxide
Ex – (i)  2Cu   +   O2         2CuO
        (ii)  4Al   +  3O2     2Al2O3
        (iii)  2Mg  +  O2      2MgO

Different Metals show different reactivitie towards Oxygen (O2)
(i)  Sodium (Na) and Potassium (K) react so vigorously that they catch fire if kept in open so they are kept immersed in kerosene.
(ii)  Surfaces of Magnesium (Mg), Aluminium (Al), Zinc( Zn), Lead (Pb) are covered with a thin layer of oxide which prevent them from further oxidation
(iii)  Fe does not burn on heating but iron fillings burn vigorously
(iv)  When Copper is heated it does not burn but is coated with black copper oxide
(v)  Gold (Au) and Silver (Ag) does not react with oxygen 

Amphoteric Oxides

Metal oxides which react with both acids as well as bases to produces slats and water are called amphoteric oxides.
Ex –
         Al2O3  +  6HCl →  2AlCl3  +  H2O
        Al2O3  +  2NaOH →  2NaAlO2  +  H2O

(B) Reaction of Metals with water (H2O)

Metal  +  Water  → Metal Oxide  + Hydrogen
Metal  Oxide  +  Water    Metal hydroxide
Ex –
     (i)  2Na  +  2H2O      2NaOH  +  H2  +  Heat
     (ii)  Ca  +  2H2O    Ca(OH)2  +  H2
     (iii)  Mg  +  2H2O    Mg(OH)2  +  H2
     (iv)  2Al  +  3H2O    Al2O3  +  3H2

>  Al, Fe and Zn React with stem
>  Na, K and Ca react with cold water
>  Mg react with hot water
>  Ca and Mg float as bubbles of Hydrogen stick to their surface
>  Pb, Cu, Au and Ag not react with water

(C)  Reaction of Metals with Acids
Metal   +  Dilute acid  →   Salt  +  Hydrogen
Cu, Ag and Hg do not react with dilute acids.
Ex –
     (i)  Fe  +  2HCl  →  FeCl2  +H2
     (ii)  Mg  +  2HCl  →  MgCl 2  + H2
     (iii) Zn  + 2HCl  →  ZnCl2  +  H2


(D) Reaction of Metals with Solutions of other Metals Salts
Metal A   +  Salt solution B    →   Salt solution A  + Metal B
*Reactive metals can displace less reactive metals form their compounds in solution form.
Ex -    Fe  +  CuSO4   →   FeSO4  +Cu




REACTIVITY SERIES
Reactivity series arranged in decreasing order from upper to lower of their reactivity
Symbols
Name

K
Potassium
Most
Reactive




Moderate
Reactive




Least  Reactive
Na
Sodium
Ca
Calcium
Mg
Magnesium
Al
Aluminium
Zn
Zinc
Fe
Iron
Pb
Lead
H
Hydrogen
Cu
Copper
Hg
Mercury
Ag
Silver
Au
Gold

Reaction of Metals with Non-Metals
Reactivity of elements is the tendency to attain a completely filled valence shell
Atoms of the metals loses electrons from their valence shell to form cation
Atoms of the non-metal gain electrons in the valence shell to form anion
Ex –
Formation of NaCl
Na ➔ Na+ + e-  (Sodium cation)
2,8,1         2,8
Sodium cation
Cl + e-  ➔  Cl-   (Chlorine anion)
2,8,7               2,8,8


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Ionic Compounds
The compounds formed by the transfer of electron form a metal to a non-metal are called ionic or  electrovalent compound.
Physical Properties of Ionic Compounds
1- Physical Nature -  They are solid and hard, generally brittle.
2- Melting and Boiling Point – They have high melting and boiling point.
3- Solubility – Generally soluble in water and insoluble in such solvent like petrol or kerosene
4- Conduction of Electricity – Ionic compounds conduct electricity in molten and solution state but not in solid state.

Occurrence Of Metals
Minerals -  The elements or compounds which occur naturally in the  earth’s crust are called minerals

Ores – Minerals that contain very percentage of particular metal and the metal can be profitable extracted from it, such minerals are called ores. 




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