E CONTENT ON METALS AND NON-METALS
METALS AND NON-METALS
INTRODUCTION
More
than 114 elements are known, which combine with each other in various ways to
form millions of compounds. On the basis of their physical and chemical
properties the elements have been classified, so that their characteristics
could be generalized and easily learnt. These are classified into two main
groups namely metals and non-metals. As we can see from periodic table, there
are only 22 nonmetals. Of these, 11 are gases (H, N, O, F, Cl, He, Ne, Ar, Kr, Xe,
Rn) one is liquid (Br) and the rest are solids. Metals are characterized by several
distinctive properties such as high electrical conductivity, metallic luster, malleability
and ductility. Non–metal does not usually exhibit such behavior.
OBJECTIVES
The
students will be able to :
·
Acquire
knowledge about Metals and Non-metals.
·
Understand
the physical properties of Metals and Non- metals
·
Explain
the chemical properties of Metals and Non-metals
·
Compare
and contrast Metals and Non-metals based on their physical properties.
·
List
examples of Metals and Non metals
·
Know
about reaction of metals and non metals
with water and acids
·
Understand
the displacement reactions
·
List
out the uses of Metals and Non-metals
CONTENTS
·
Introduction
to Metals
·
Introduction
to Non-metals
·
Properties
of Metals and Non-metals
·
Uses
of metals and Non-metals
SUBCONTENTS
·
Physical
properties of metals
·
Chemical
properties of metals
1.
Reaction
with oxygen
2.
Reaction
with water
3.
Reaction
with acids
4.
Reaction
with metal salt solution
·
Physical
properties of non- metals
·
Uses
1.
Metals
2.
Non-metals
Metals
Only
eight metals were known to ancient people (ashtadhatu) -copper, silver, gold, iron,
tin, lead, mercury and antimony. Several hundred years ago, alchemists wanted
to prepare precious metals like gold from base metals like iron, copper,
or lead. Today we know about 80 metals, their properties and uses. metals are
used for the construction of bridges, trains, ships, automobiles, etc. Metals
are the elements which form positive
ions by losing electrons.
Physical properties of metals
MetallicLustre: The
property of metals having shining surface is called metallic lustre. In pure
state, metals have shining surfaces. For example gold, silver, and copper have
metallic lusture.
Malleability
:
Ductility:
Metals like copper,
aluminium,etc., can be drawn into thin wires. This property is known as
ductility.You can draw a wire of about 100 m from 50 mg of silver metal.it is due to
the property of malleability and ductility , that metals can be given different
shapes.
Hardness
:
Metals are generally
hard in nature. Eg: iron, copper, gold , etc.
Conductors
of heat and electricity :
Metals are good conductors of
heat and electricity that is it allows
heat and electricity to pass through it easily. Aluminium is a good
conductors of heat while lead is poorest, among the metals.
Eg : gold, copper,
iron . etc
Sonority :
The property of producing a deep
ringing sound is called sonorous. Metals
are used for making bells and strings of musicals instruments due to this property.
REACTIONS OF
METALS
Reaction with oxygen :
Almost all metals react with oxygen to form metal oxides. The
metals lose electrons which are gained by oxygen.
4Na + O2 → 2Na2O (sodium oxide)2Mg + O2 → 2MgO (magnesium oxide)
Metal oxides are basic in
nature. Some of the metal oxides react with water to form alkalies.Metals
like Na and K react vigorously with oxygen. They catch fire even when kept in air forming oxides.Mg
is less reactive than sodium or pottassium.It has to be heated before it
combines with oxygen.
Reaction with water
Metals react with water to form metal oxides or metal
hydroxides and hydrogen.
2Na + 2H2O → 2NaOH
2K + H2O → 2KOHCa + H2O → Ca(OH)2 + H2
The reactivity of different metals with water is different
-
Na and K react violently with cold water to form NaOH and
hydrogen and catches fire.
-
Calcium react less violently with water to form calcium
hydroxide and water and does not catch fire
-
Mg reacts only with hot water to form magnesium hydroxide and
hydrogen
-
Metals like lead, copper, silver and gold do not react with
water.
Reaction
with acids
Metals react with dilute acids to form salts and hydrogen.
Mg + 2HCl → MgCl2 + H22Al + 6HCl → 2AlCl3 + 3H2
→Zn + 2HCl
ZnCl2 + H2
Fe +
2HCl → FeCl2 + H2
The reactivity various
from metal to metal. For the above metals the decreasing order of reactivity is
Mg> Al> Zn>Fe. Copper,silver,and
gold do not react with dilute HCl.
Rection with metal salt solution
More reactive metals displace less reactive metals from their
metal compounds in aqueos solution. displacement reactions
Magnesium diaplces copper from copper sulphate solution
Mg + CuSO4 → MgSO4 + Cu
Iron displaces copper from copper sulphate solution
Fe + CuSO4 → FeSO4 + Cu
Videoattachment: https://www.youtube.com/watch?v=WsrdE5g4z1I
Non-Metals
In
chemistry, a non-metal is
a chemical element that mostly
lacks metallic attributes. Physically, nonmetals tend to be
highly volatile (easily vaporized), have low elasticity, and are good insulators of heat
and electricity; chemically, they tend to have high ionization energy and electronegativity values, and gain or share electrons when they
react with other elements or compounds.
Physical properties of Non -metals
·
Non
-metals are generally light in weight
·
Solid
non-metals are generally light in weight
·
They
are bad conductors of heat and electricity (except graphite)
·
They
are neither ductile nor malleable
·
Their melting point and boiling point are
generally low
·
They
do not produce ringing sound
·
They
are generally non lustrous and cannot be polish.
REACTIONS OF NON-METALS
Acidic oxides are formed
from non-metals. They are usually gases at room temperature and dissolve in
water to form acidic solutions with pH less than 7.
Example :
CO2 (g) + H2O
(l) → H2CO3
(aq)
Acidic oxides react with
alkalis to form a salt and water
Example:
CO2 (g) + 2NaOH (aq) → Na2CO3
(aq)
+ H2O (l)
Videoattachment:
Uses of Metals
·
Iron
is used in making machinery, buildings , car, motorcycle, ships, bridge, etc.
·
Copper
is used in making electric wires, statue, etc.
·
Aluminium
is used in making kitchen utensils, electric wire,etc.
·
Gold
is used in making in ornaments.
·
Silver
is used in making ornaments. calcium compounds are used for making cement,
glass, etc.
Uses of non-metals
·
Hydrogen
is used in the hydrogenation of vegetable oils to make vegetable ghee. It used
in the manufacture of ammonia. Liquid hydrogen is used as a rocket fuel.
·
Carbon
is used for making electrodes of
electrolytic cells
·
The
oxygen cyliders are used to help patients in breathing .
·
The
animals and plants use oxygen for respiration.
·
Iodine
is used as a antiseptic
·
Nitrogen
is used by plants for fixation in the
form of nitrates. Liquid nitrogen gives
very low temperature and hence it is used to preserve food, tissues
and human organs.
Videoattachment:
SUMMARY
Metals are hard ductile,sonorious,shining, malleable, conduct electricity and heat,and having high
melting point.
The properties of non-metals include low melting point,dull, brittle,soft,do not
conduct heat and electricity, non-sonority.Metals react with water, acids
,bases etc.
Important metals
include iron, alumnium ,copper ,gold,
etc. , which are used in various applications including construction of
buildings, cars, ornaments, etc. Important non – metals in our daily lives are
oxygen, nytrogen, hydrogen etc.
The oxides of metal are basic in nature as they form bases on
addition of water. The oxides of non- metal are acidic oxides as they dissolve
water to give acids.
GLOSSARY
Acidic oxide: An oxide that react with water to produce
an acid
Malleable : Capable
of being extended or shaped by hammering or by pressure from rollers.
Ductile : Able to be
drawn out into a wire.
Sononous: Capable of producing a deep or
ringing sound.
FAQ
·
Write the uses of metals
and non-metals.
·
Write the difference
between metals and non-metals on the basis of their physical properties.
·
Name two most ductile
metals.
·
What are oxides? Write the
nature of metallic and non-metallic oxides.
·
Explain displacement
reaction with the help of an example.
·
Explain the reactions of
metals and non-metals with (i) Acids (ii) Air (iii) Water.
·
Write the uses of metals and
non-metals in our daily life?
·
Why sodium kept immersed in
kerosene oil?
·
Name one non-metal and one
metal , which are in liquid state at room temperature ?
EXERCISES
v
Take a piece of magnesium ribbon. Burn it using a matchstick
and introduce it into a gas jar. Check
the reactivity of magnesium with oxygen.
v
Take dry cell, a torch bulb, connecting wires , crocodile
clips and connect them
→isn’t metal conducts electricity?
v
Take a copper rod and clamp it to a stand. Paste iron nails
to the copper rod, with the help of wax. Heat the rod. What do you observe ?
the iron nails attached to the copper
rod fall one by one. The iron nails , which is closer to the flame falls
first. This shows that the metals are good conductors of heat.
REFERENCE
·
Metals and non-metals /https://www.thoughtco.com/metals-versus-nonmetals-608809
·
Examples and uses of metals and non metals
/https://www.thoughtco.com/name-5-nonmetals
-and-5-metals-606680
·
Non metals photo gallery
/https://www.thoughtco.com/nonmetals-photo-gallery-4054182
·
Acidic
oxide/http://groups.molbiosci.northwestern.edu/holmgren/Glossary/
Definitions/Def-A/acidic_oxide.html
·
Metals and non metals
/https://www.youtube.com/watch?v=NKw-2A92TiA
·
Metal and non
metal part -1/https://www.youtube.com/watch?v=UzeU_LHTCzQ
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