01.
3. Metals and Non-metals
Elements can be classified as metals or non-metals on the basis of their properties.
Properties :
1) Metallic lustre :
Metals, in their pure state, have a shining surface. This property is called metallic lustre.
2) Malleability :
Some metals can be beaten into thin sheets. This property is called malleability.
3) ductility :
The ability of metals to be drawn into thin wires is called ductility.
Because of their malleability and ductility that metals can be given different shapes
according to our needs.
4) Sonorous :
The metals that produce a sound on striking a hard surface are said to be sonorous.
I) PHYSICAL PROPERTIES :
PROPERTY METALS NON-METALS
1) Lustre : - Metals have shining surface. - Metals have shining surface.
- Except Iodine.
2) Hardness : - They are generally hard. - Generally soft.
- Except Sodium, Lithium and - Except Diamond, a form
Potassium which are soft and of carbon which is the
can be cut with knife. hardest natural substance.
3) State : - Exist as solids. - Exist as solids or gaseous.
- Except Mercury. - Except Bromine.
4) Malleability : - Metals can be beaten into thin - Non-metals are nonmalleable.
sheets.
- Gold and Silver are the most
malleable metals.
5) Ductility : - Metals can be drawn into thin - They are non-ductile.
wires.
6) Conductor of - Metals are good conductors of - Non-metals are poor conductor
heat & electricity : heat and electricity. of heat and electricity.
- Silver (Ag) and Copper (Cu) Best
conductors of heat.
- Lead (Pb), Mercury (Hg) poor - Except Graphite.
conductor of heat.
, 02.
PROPERTY METALS NON-METALS
7) Density : - Generally have high density and - Have low density and low
high melting point. melting point.
- Except Sodium and Potassium.
8) Sonorous : - Metals produce a sound on - They are not sonorous.
striking a hard surface.
9) Oxides : - Metallic oxides are basic in - Non-metallic oxides are
nature. acidic in nature.
10) E.g : - Iron (Fe), Aluminium (Al), - Hydrogen (H), Nitrogen (N),
Silver (Ag), Copper (Cu) Sulphur (S), Oxygen (O)
Properties of Ionic Compounds :
Na ------------> Na+ + e- Cl + e- ------------> Cl+
2,8,1 2,8 2,8,7 2,8,8
(Sodium cation) (Chloride anion)
xx xx
x x
Na + Cl -------------> Na+ + Cl-
x x x x
xx xx
1) Sodium atom has one electron in its outermost shell.
2) If it loses the electron from its M shell then its L shell now becomes the outermost shell
and that has a stable octet.
3) The nucleus of this atom still has 11 protons but the number of electrons has become 10,
so there is a net positive charge giving us a sodium cation Na+.
4) On the other hand chlorine has seven electrons in its outermost shell and it requires one
more electron to complete its octet.
5) If sodium and chlorine were to react, the electron lost by sodium could be taken up by
chlorine.
6) After gaining an electron, the chlorine atom gets a unit negative charge, because its
nucleus has 17 protons and there are 18 electrons in its K, L and M shells.
7) This gives us a chloride anion Cl–. So both these elements can have a give-and-take
relation between them.
8) Sodium and chloride ions, being oppositely charged, attract each other and are held by
strong electrostatic forces of attraction is known as ionic bond.
9) E.g of ionic compound : NaCl, MgCl2
10) The transfer of electrons from a metal to a non-metal are known as ionic compounds or
electrovalent compounds.
3. Metals and Non-metals
Elements can be classified as metals or non-metals on the basis of their properties.
Properties :
1) Metallic lustre :
Metals, in their pure state, have a shining surface. This property is called metallic lustre.
2) Malleability :
Some metals can be beaten into thin sheets. This property is called malleability.
3) ductility :
The ability of metals to be drawn into thin wires is called ductility.
Because of their malleability and ductility that metals can be given different shapes
according to our needs.
4) Sonorous :
The metals that produce a sound on striking a hard surface are said to be sonorous.
I) PHYSICAL PROPERTIES :
PROPERTY METALS NON-METALS
1) Lustre : - Metals have shining surface. - Metals have shining surface.
- Except Iodine.
2) Hardness : - They are generally hard. - Generally soft.
- Except Sodium, Lithium and - Except Diamond, a form
Potassium which are soft and of carbon which is the
can be cut with knife. hardest natural substance.
3) State : - Exist as solids. - Exist as solids or gaseous.
- Except Mercury. - Except Bromine.
4) Malleability : - Metals can be beaten into thin - Non-metals are nonmalleable.
sheets.
- Gold and Silver are the most
malleable metals.
5) Ductility : - Metals can be drawn into thin - They are non-ductile.
wires.
6) Conductor of - Metals are good conductors of - Non-metals are poor conductor
heat & electricity : heat and electricity. of heat and electricity.
- Silver (Ag) and Copper (Cu) Best
conductors of heat.
- Lead (Pb), Mercury (Hg) poor - Except Graphite.
conductor of heat.
, 02.
PROPERTY METALS NON-METALS
7) Density : - Generally have high density and - Have low density and low
high melting point. melting point.
- Except Sodium and Potassium.
8) Sonorous : - Metals produce a sound on - They are not sonorous.
striking a hard surface.
9) Oxides : - Metallic oxides are basic in - Non-metallic oxides are
nature. acidic in nature.
10) E.g : - Iron (Fe), Aluminium (Al), - Hydrogen (H), Nitrogen (N),
Silver (Ag), Copper (Cu) Sulphur (S), Oxygen (O)
Properties of Ionic Compounds :
Na ------------> Na+ + e- Cl + e- ------------> Cl+
2,8,1 2,8 2,8,7 2,8,8
(Sodium cation) (Chloride anion)
xx xx
x x
Na + Cl -------------> Na+ + Cl-
x x x x
xx xx
1) Sodium atom has one electron in its outermost shell.
2) If it loses the electron from its M shell then its L shell now becomes the outermost shell
and that has a stable octet.
3) The nucleus of this atom still has 11 protons but the number of electrons has become 10,
so there is a net positive charge giving us a sodium cation Na+.
4) On the other hand chlorine has seven electrons in its outermost shell and it requires one
more electron to complete its octet.
5) If sodium and chlorine were to react, the electron lost by sodium could be taken up by
chlorine.
6) After gaining an electron, the chlorine atom gets a unit negative charge, because its
nucleus has 17 protons and there are 18 electrons in its K, L and M shells.
7) This gives us a chloride anion Cl–. So both these elements can have a give-and-take
relation between them.
8) Sodium and chloride ions, being oppositely charged, attract each other and are held by
strong electrostatic forces of attraction is known as ionic bond.
9) E.g of ionic compound : NaCl, MgCl2
10) The transfer of electrons from a metal to a non-metal are known as ionic compounds or
electrovalent compounds.
