Digital text on metal

3. THE
NATIONAL
ANTHEM
Jana-gana-mana
adhinayaka
jaya
he
Bharatha-bhagya-vidhata,
Punjab-Sindh-Gujarat-Maratha
Dravida-Utkala-Banga
Vindhya-Himachala-Yamuna-Ganga
Uchchala-Jaladhi-taranga
•
Tava
subha
name
jage,
Tava
subha
asisa
mage,
．
．
Gahe
tava
jaya
gatha..
Jana-gana-mangala-dayaka
jaya
he
Bharatha-bhagya-vidhata,
Jaya
he,
jaya
he,
jaya
he,
Jaya
jaya
jaya
jaya
he!
PLEDGE
India
is
my
country.
All
Indians
are
my
brothers
and
sisters
.
I
love
my
country,
and
I
am
proud
of
it'
s
rich
and
varied
it
heritage.
I
shall
always
try
to
be
worthy
of
it
.
I
shall
give
respect
to
my
parents,
teachers
and
all
elders
and
treat
everyone
with
courtesy
.
To
my
country
and
my
people
,I
pledge
my
devotion
in
their
well
being
and
prosperity
alone
lies
my
happiness.
1

5. Dear
Students,
Science
is
the
knowledge
that
man
has
gained
through
the
process
of
experimentation,
observation
and
analysis.
Study
of
science
should
be
made
a
pleasant
experience
by
giving
emphasis
to
the
basic
methods
of
science
like
experimentation,
observation,
analysis
and
elucidating
inferences.
While
familiarising
ourselves
with
new
concepts
and
areas
of
knowledge,
we
should
also
be
keen
on
acquiring
and
developing
Certain
values
and
attitudes.
Chemistry
has
played
a
significant
role
in
giving
new
dimensions
to
human
civilization
and
also
in
improving
the
living
standards
of
individuals.
It
can
be
said
without
doubt
that
there
is
no
branch
of
science
other
than
chemistry
that
has
influenced
mankind
to
such
a
great
extent.
Wishing
you
the
best
ARYA.
S
2

6. METALS
3

8. Are
you
familiar
with
this
picture
This
periodic
table
is
the
classification
of
elements,
isn't
it
From
this
periodic
table
can
you
say
the
name
of
some
metals?
Oh
good.
So
you
are
aware
of
metals
Around
90
of
the
total
118
elements
are
metals
4

9. Did
we
use
metals
in
our
daily
lives?
Why
they
are
extensively
used?
Is
this
due
to
some
properties
of
metal
s?
How
do
you
konw
whether
an
object
is
made
of
metal?
By
heating
Bytestingitshardness
...............................
.................................
GENERAL
CHARACTERISTICS
OF
METALS
MALLEABILITY
Are
the
metals?
Are
Aluminum
foil,
plate
and
gold
foil
thin?
How
they
can
be
made
so
thin?
So
from
this
could
you
understand
that
metals
can
be
beaten
in
tO
thin
sheets.
This
property
of
metal
is
known
as
malleabilit
y
5

10. In
these
picture
is
the
metals
are
in
malleable
form?
Yes,
they
are
not
then
they
are
converted
to
what?
So
from
this
you
could
understand
that
metals
can
be
drawn
in
to
thin
wires
This
property
is
known
as
ductility
Malleability
Metals
can
be
beaten
in
to
thin
sheets
by
hammering.
This
property
is
known
as
malleability
Try
to
find
more
instances
where
malleability
of
metals
are
emplyed
DUCTILITY
CAN
YOU
GUESS
Which
is
the
most
malleable
metal
G...L....
answer
-Gold
DUCTILITY
metals
can
be
drawn
in
to
thin
wires
this
property
is
known
as
ductility
Suggest
some
more
instances
where
ductility
of
metals
are
employed
6

11. We
use
metallic
substances
to
make
agriculture
equipments
do
you
know
why?
Hardness
is
yet
another
property
of
metals
Solve
the
maze
correctly
by
using
the
answer
of
the
question
Which
property
of
metal
is
employed
in
making
the
filament
of
incandescent
bulbs?
Malleability
Ductility
Hardness
7

12. Take
a
piece
of
sodium
and
cut
it
using
a
knife.Similarly
take
a
piece
of
iron
and
aluminum
and
try
to
cut
it
with
knife
We
have
learned
that
hardness
is
the
property
of
metals,
haven't
you?
Yet,
are
all
metals
hard?
Ok
let's
know
we
can
do
an
experiment
What
is
your
observation?
Can
you
cut
sodium
using
knife?
What
about
Iron
and
Aluminium
From
this
is
the
hardness
of
iron
or
aluminium
with
that
of
sodium
be
the
same?
So
from
this
we
can
understand
that
some
metals
are
soft
like
sodium
Lithium,
Sodium,
Pottassium
are
soft
metals
they
can
be
cut
easily
with
a
knife
8

13. METALLIC
LUSTRE
When
we
cut
sodium
in
the
previous
experiment
do
you
notice
the
newly
formed
surface?
What
is
its
peculiarity
compared
to
old
surface?
Yes
it
is
lustrous
THERMAL
CONDUCTIVITY
Let's
do
an
experiment
Take
a
lighted
candle
show
an
iron
rod
in
to
the
flame
for
some
time
Did
you
felt
heat?
Why
did
you
felt
heat?
Yes
metals
can
conduct
heat
Metals
are
thermal
conductors
9

14. Metallic
vessels
are
used
for
cooking
which
property
of
metal
is
mainly
employed
here?
Electrical
conductivity
Which
material
is
used
inside
this
electric
wire?
Yes
copper?
Is
it
a
metal?
So
which
property
of
metal
is
used
here?
Metals
are
good
conductors
of
electricity
10

15. Sonority
Let's
do
an
experiment
Take
a
metallic
vessel
and
an
earthen
pot
tap
gently
with
a
steel
sppon
on
both
the
vessels
What
difference
do
you
noticed
in
the
sounds
produced
We
generally
use
metals
for
making
school
bells,
cymbals
and
the
like
do
you
know
why?
What
happens
if
we
use
wood
or
plastic
materials
instead
of
metals?
Yes
the
sound
produced
will
be
different
and
not
much
sound
is
produced
.so
this
is
a
property
of
metals
it
is
known
as
sonority
The
ability
of
metals
to
produce
sound
when
tapped
with
a
hard
material
is
known
as
sonority
Metals
generally
melt
at
high
temperature
and
possess
high
density
Metals
like
Galium,
cesium
and
mercury
melt
at
low
temperatures
Metals
like
Lithium,
Sodium
and
Magnesium
are
low
density
metals
11

16. General
properties
of
metals
in
a
nutshell
Malleability
Ductility
Hardness
Metallic
lustre
Thermal
conductivity
Electrical
conductivity
Sonority
High
mel
4th
ing
point
High
density
We
have
learned
some
general
properties
of
metals.
Metals
also
have
some
chemical
properties
do
you
know
what
they
are?
Is
that
same
for
ever
metals
Look
at
some
instances
Iron
articles
kept
outside
ourhouses
get
destroyed
through
resting
over
a
period
of
time
Gold,
silver
and
platinum
are
usually
used
for
making
ornaments
Buttermilk
is
not
stored
in
aluminum
vessels
Clav
is
formed
on
copper
vessels
Have
you
ever
thought
of
the
reason
behind
this?
Let's
know.............
12

17. REACTION
WITH
AIR
Cut
a
small
piece
of
sodium
with
a
knife,observe
the
metallic
lustre
at
the
newly
formed
surface
kept
it
exposed
to
air
for
some
time
and
look
the
change
happened
to
the
metallic
lustre
What
happened
to
the
surface
what
could
be
the
reason?
Similarly
take
an
aluminum
rod
rub
it
with
sand
paper
observe
the
lustre
of
the
rubbed
surface
keep
ot
for
some
days
in
exposure
to
air
What
happens
to
the
lustre
of
aluminum?
What
may
be
the
reason?
When
metals
came
in
to
contact
with
atmosphere,
they
undergo
chemical
reaction
with
different
components
of
air.As
a
result
metal
loses
its
lustre
and
get
tarnished
REACTION
WITH
WATER
Take
two
beakers
filled
with
water
put
a
piece
of
sodium
in
one
of
the
beakers
and
put
a
pice
of
copper
in
the
other.
Observe
carefully
Did
the
reaction
at
the
two
beaker
will
be
the
same?
In
which
beaker
does
a
vigorous
reaction
occured?
Yes
in
the
sodium
containing
beaker
So
is
the
reaction
of
sodium
and
copper
with
water
be
the
same?
Which
one
reacts
more
vigorously?
yes,it
is
sodium
2Na+2H
2
O------>2NaOH+H
2
From
the
above
equation
can
you
identify
the
gas
liberated
during
the
reaction
of
sodium
with
water?
Sodium
13

18. The
metals
Potassium
and
calcium
also
react
vigorously
with
cold
water
Write
down
the
chemical
equation
for
the
reaction
of
calcium
and
potassium
with
water?
......................................................
......................................................
Under
favourable
conditions
,
certain
metals
react
with
water
to
form
hydrogen
gas
REACTION
WITH
ACID
Take
a
test
tube
having
dilute
hydrochloric
acid
put
some
pieces
of
zinc
into
the
test
tube,
after
that
repeat
the
experiment
using
aluminium,
iron
and
magnesium
What
do
you
have
observed?
Did
there
is
the
liberation
of
any
gas?
If
so
which
is
the
gas?
How
di
DC
you
identified
the
gas?
Zn+2HCl------->ZnCl
2
+H
2
Write
down
the
chemical
equation
for
the
reaction
of
Aluminum,
Iron
and
Magnesium
with
dilute
hydrochloric
acid?
..................................................................
..................................................................
..................................................................
14

19. Chemical
properties
of
metals
15

20. Corrosion
of
metals
Corrosion
is
one
of
the
most
common
phenomena
that
we
observe
in
our
daily
lives.
You
must
have
noticed
that
some
objects
made
of
iron
are
covered
with
an
orange
or
reddish-brown
coloured
layer
at
some
point
in
time.
The
formation
of
this
layer
is
the
result
of
a
chemical
process
known
as
rusting,
which
is
a
form
of
corrosion.
Corrosion,
in
general,
is
a
process
through
which
refined
metals
are
converted
into
more
stable
compounds
such
as
metal
oxides,
metal
sulfides,
or
metal
hydroxides.
Likewise,
the
rusting
of
iron
involves
the
formation
of
iron
oxides
via
the
action
of
atmospheric
moisture
and
oxygen.
If
we
look
at
the
science
behind
corrosion,
then
we
can
say
that
it
is
a
spontaneous/
irreversible
process
wherein
the
metals
turn
into
a
much
more
stable
chemical
compound
like
oxides,
sulphides,
hydroxides,
etc.
Some
metals
react
with
different
components
of
air
and
form
new
products.This
process
is
known
as
corrosion
of
metals
16

21. Factors
affecting
corrosion
Let's
do
a
project
MATERIALS
REQUIRED
Clean
and
dry
test
tubes
-
4
Nos
Rust-free
and
clean
iron
nails-4Nos
Quick
lime.
-10g
Sodium
chloride
solution
-25mL
Cork-1
PROCEDURE
Put
iron
nails,
one,
each
in
the
four
test
tubes
Drop
a
small
piece
of
moist
cotton
in
first
test
tube
and
keep
it
exposed
to
the
atmospheric
air
In
the
second
test
tube
,put
some
quick
lime
and
keep
it
closed(quick
lime
absorbs
moisture)
In
the
third
pour
some
sodium
chloride
solution
such
that
half
of
nails
stay
immersed
in
it
In
the
fourth
test
tube,pour
some
dilute
hydrochloric
acid
/vinegar
to
immerse
half
of
the
nail.
OBSERVATIONS
TEST
TUBE1-Presence
of
rust
TEST
TUBE2-no
rust
TEST
TUBE3-maximum
rest
TEST
TUBE
4
-maximum
rest
From
this
project
can
you
name
the
factors
affecting
corrosion?
..................................................................
..................................................................
....................................................................
17

22. •
•
Name
some
metals
that
are
generally
used
for
making
ornaments?
Why
they
are
used
so?
Do
they
have
any
special
properties?
Gold,
silver,
platinum
are
resistant
to
corrosion
so
this
metals
are
extensively
used
to
make
ornaments
Now
can
you
suggest
some
measures
to
prevent
the
corrosion
of
metals
?
....................................
....................................
....................................
...................................
18

23. EXTRA
READING
MATERIALS
19

24. 20

25. EXERCISES
21

26. Solve
the
puzzle
22

27. Find
out
the
hidden
words
related
to
metals
In
the
following
table
there
are
5
general
properties
of
metals
find
them
23

28. ODD
ONE
OUT
1.
2.
3
24

29. LET
US
ASSESS
1.
Some
metals
are
listed
below.
Complete
the
table
by
identifying
the
different
uses
and
properties
which
are
responsible
for
the
same
2.Iron
is
a
metal
which
corrodes
fast
what
are
the
factors
that
favours
the
corrosion
of
iron
?
In
coastal
regions
copper
nails
are
preferred
to
Iron
nails
what
could
be
the
reason
?
can
you
suggest
some
measures
to
prevent
the
corrosion
of
iron?
3.Based
on
the
physical
properties
of
metals,
indicate
whether
the
following
statements
are
true
or
false
25

30. 4.Which
among
the
following
metal
is
stored
in
kerosene
a)
sodium
b)
iron
c)
tungsten
D)
chromium
why
is
it
stored
in
kerosene
?
5.The
names
of
some
metals
are
given
below
tungsten,
gold,
sodium
,copper,
iron
,magnesium
Answer
the
following
questions
by
selecting
the
appropriate
Ones
from
the
list
which
metal
with
high
malleability
is
used
for
making
ornaments
which
of
these
metals
react
with
cold
water
which
of
these
is
a
hard
metal
but
corrodes
easily
6.Give
reasons
for
the
following
statements
Tamarind
is
not
stored
in
aluminium
vessels
It
is
a
common
practice
to
apply
oil
on
Iron
articles
and
tools
Stainless
Steel
knives,
instead
of
Iron
knives,
are
preferred
for
cutting
citrous
fruits
EXTENDED
ACTIVITIES
26

31. 27

32. NOTES
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