Eyq yn - F'Y, 0.5
c Ccg b cnst SuYn ry
Model Answer of chemistry Paper
II
P Code- 755801 dated 2311112016
Select the correct option (MCQ)
Which property measures the resistance of a liquid to flow?
Rain drops are spherical in shape because
of----------
The half life time of the first order reaction is ------- of the initial
concentration of the reactant.
Which three factors affect the rate of a chemical reaction?
c) temoerahne. reactant concentration and
Which of the following is not allotrope of carbon
The outer electronic configuration of group 14 elements is --ns2. no2
Oxidation state ofNitrogen in HNO3
is--
Ion O2'- is called---ion.
In flying wedge formula 'wadge' represents a bond
----
plane of the paper
Main condition for optical activity is
-----
is the stable configuration of ethane
But-2-ene has ------ geometrical isomers
For
a pseudo
statements are true or false
unimolecular reaction, order is two and molecularity is one.
False
Electronegativity of fluorine is more than that of chlorine
True
Dextrorotatory enantiomers is designetaed by using symbol
'L'
False
Stalagmometer
Staggered conformation
Amphoteric
Caustic soda
Unit for ltt order rate constant
- Surface Tension
- conformation with lower energy
- AlzOr
- NaOH
- time-l
1) The rate ofsecond order reaction is
uence by the concentration of two
reactants.
2) The rate constant for second order
the two reactants is given by the equati
with equal initial concentrations of
K=*#)
of the reactant'A' and'B'.
'A' & 'B' reacted in time t sec.
teactantA and B remaining at time 't'
sec.
ls-l.
3) The unit of 'K' will be concentration-r time-l or dm3mol
for half the reaction is inverselY
4) For second order reaction, the time
proportional to the initial concentrations
or tt/rn"/o
Thus, trTr=
"/ox
5) When'x/(a-x)' is plotted against time 't', it gives a straight line passing through
:
the origin with slope Ka
6) When 'll(a-x)' is plotted against time
ual to K and intercePt on Y;q4P a!-!
Order of Reaction - The sum of all the
rate equafion are ra$e.
't', it gives a straight line with slope
to which the concentration in the
concentration (or Pressure)
The number of molecules (or atoms)
determines the rate of reaction is called
the concentration ofthe reactant or
Rate of Reaction - The rate of change
Graphical MethodIn the determination of order of a
and '(a-x)' at different time interval 't'
from the experimental observations.
Then assuming the order of reaction
by graphical method, the value of 'a'
evaluated for a given chemical reaction
and
tlowing graphs are plotted, for first order
) log(a - x) against 't' and for second
ion ofthe reactants - (1) x/(a-x) against
and(2) l/(a-x) against't'.
If the graph of log*i against't'
a straight line passing through the origin
logf,
against't'
order reaction with equal initial
't'
in diagram and a graPh of
intercept on Y-axis with negative
as shown
points
1M
each
where 'a'- is initial concentration of
'x' -is the concentration of each of the
(a-x) - is the concentration ofeach of
reaction - (f )
Any
five
a
with
- x) against 't' also a straight line
equal to
then the order of reaction
will be
Saph
of l/(a-x) against 't'
gh the orign and a
of reaction will
order
as shown in diagram, then, the
general, if n is the order of reaction, a plot of
slope =
(n-l)K
Given:
and intercept =
the order of reactions. In
against 't' will be a straight
a:f;;-,
Afu
lsec-l'
K - 6.173 x 10-3 dm3mol
a = 0.01 mol dm-3'
concentratiolrEqual initial
Rate constant
-
tt/z= t
W6 mow that the half life time for second order reacti on
"'tr/r=#=#=L6,ase.s7sec
is tt 1 r= t 1 o*
B
D
Explain refractive index, specific refraction and molar refraction.
,.
:
,
".jr
n
wi{}:
hrl*{}ac"*s}"iefu **-i n {h*-
Jhe,"-m"nqi"{s*.,irr.
rnnnd hu{l:ann5e*nn*r
,,r..;,
(5)
.l
The density of
-",hyt
ll*:$::djum
D-line is 1.3s94. Calculate its molar refractiviry. ( Given:
Molecular weight of methyl acetate:74)
*
l..[sfo* R.fi,*rli(rn
Rx
tr,,r
=
-1S,.r
rnEii
(t.u11
'Ihe rate
of inversion of cane sugar is of the first order. If 2-% oFsample of
cane sugar is hydrolyzed in 50 seconds, how long will it take for 50yotobe
hydrolyzed?
1M
GivenChange in concentration when t = 50 sec
,
the amount of cane sugar hydrolyzed - x:25%o
.'.the change in concentration at 50 sec = (a
- x) = 100 -
Let, initial concentration (a) : 100% i.e.when
t:
25 = 7 5yo
0
2M
For the first order reaction
x=
2#tos*-*
..........@
:,
K
2.303 100
= 50 loo'-o 75
= 0.00575 sec-r.
Change in concentration at time
.'. (a-x)
:
100
is (x) :50%o
- 50: 50 %
. 2.303 ,
a
t=Ttog1_,-o
t=
't'
............@
(from equation O)
offi log#
(from equation @)
120.25 sec
c
OR
i)
The viscosity of a liquid at293Kis 0.084 Nsm-2 ana its Oensity is 1.1 x
10'kg.m-'. How long will it take to pass through a viscometer if water under
the same condition takes 30 s? (Given: viscosity of water: 0.00101 Nsrnz
kg.m-'.)
,density of water:0.998 x l03kg.m-3
(4)
a A
D
ln what ways does beryllium differ from other alkaline earth metals
?
(4)
3
Ans
The main points of differences are given below
(i)
:
lt is hardest of all alkaline earth metals : This is due to the fact that
maximum metallic bonding is present on account of the smallest size
amongs alkaline earth metals.
The melting and boiling points of the beryllium are the highest : This is
also due to maximum metailic bonding.
lt is not affected by atmosphere : Be is least reactive as its ionisation
potential is high. However, it does react with oxygen and nitrogen at
high temperatures.
lt does not decompose water : This is due to low value of oxidation
(ii)
(iii)
(iv)
(v)
potential.
lt has the tendency to form covalent compounds : The polarisation
effect of Be" ion is high due to its high charge density. The large
distortion of electron cloud of the anion brings covalent character. Be
has high value of electronegativity (1.5) and when it reacts w1h another
element, the electronegativity difference is not so large and the bond is,
therefore, covalent.
lt does not react directly with hydrogen : Beryllium hydride can,
however, be formed by reducing BeCl2 with LiAlH4. Beryllium hydride is
a covalent compound. lt is polymeric solid, (BeH2)n. lt contains
hydrogen bridges between beryllium atoms.
The hydrides of ca, sr and BA are largely ionic due to greater electropositive
character.
lt dissolves in alkalies with evolution of hydrogen :
Be +2NaOH + 2HzO- NazBeOz.2H2O + H2
lt does not liberate hydrogen from acids readily : This is due to the fact
that Be has lowest oxidation potential amongst alkaline earth metals.
(vi)
(vii)
(viii)
ii)
Explain the diagonal relationship between boron and silicon.
(4)
Ans B and Si
Boron shows resemblance with silicon, the second typical element of group 14 of
the next higher period. This type of relationship between diagonally placed
elements is called diagonal relationship
Group 13
Second
period
Group 14
B
Third period
Following are the properties where boron and silicon show close resemblance
(i)
(ii)
fiiil
:
Both boron and silicon are non-metals. Both have high melting points
oC
; Si = 14100C], high ionisation energieJlB = 8.3eV, Si=
[B = 2300
8.20 eV) and are bad conductors of electricity at normal temperature.
Both have nearly equal electronegativity B = 2.0; Si = 1.8
Both boron and silicon show allotroov.
(iu)
(v)
Most of the c
Boron and silicon burn in air on heating forming stante oiiaes B2o3 and
sio2 respectively. The oxides are acidic and cJmbine with arkalies
lorming borate and silicates respectively.
B2O3 + 6NaOH --+ 2NagBOg + 3HzO
SiO2 + 2NaOH + Na2SiO3 + H2Q
Both boron and silicon combine with metals to form borides and
silicides respectively.
(vi)
28 + 314n -- MgeBz
lllustrate the anomalous behaviour of fluorin"
.*li*aE
ott*
halogens.
rest
(iii
Th
Ans:- Fluorine differs from
(ii) highest electronegativity,
orbitals in the valence shell.
e to (i) its small size
and iiv) absence of d_
:
(1) Fluorine is most reactive of all the halogens due to lower value of F
F bond
dissociation energy (Fz = 158, cl2=243, bromine = 192 and iodine 1s1 kJ mofl)
=
-
(2) Being the most electronegative element, it shows only an oxidation state of
-1
and does not show positive oxidation states due to absence of d-orbitals in its
valence shell. other halogens show positive oxidation states of +1, +3, +5 and +7.
(3) Due to small atomic size and high electronegativity of H, HF undergoes
strong H-bonding while other halogen acids do not. As a result,
(i) HF is a liquid (boiling point 292.sK), while other halogen acids are gases at room
temperature (boiling point of HCI = 189 K, HBr = 206 K, Hl = 238 K).
(ii) HF is weakest of all the halogen acids due to high strength of H
F bond.
(iil).Oy9]o H-bonding, HF can form acid satts of the type KHF2, ri.e.,-K*[H
-
F ...
while HCl, HBr and Hl do not form such salts (1e., no KHCI, KHBr2 and KHl2 are
Fl
known).
(4) Fluorides have the maximum ionic character. For example AlF3 is ionic while
other halides of are covalent.
F2 is
so powerful oxidising agent that it can even oxidise inert-gases.
(6) HF cannot be stored in glass bottles since it reacts with silicates to form
fluorosilicates.
Na2SiO3 + 6 HF
while other halogen acids (HCl, HBr and Hl) do not react with silicates and hence
can be stored in glass bottles.
(7) AgF is soluble in H2O while all other silver halides r'.e., AgCl, AgBr and Agl are
insoluble in water. In constant, CaFz is insoluble while other calcium
hafides i.e.,CaCl2, CaBr2, Cal2a'e soluble inHzO.
(8) Due to absence of -orbitals, fluorine, does not form polyhalide ions while other
halogens form polyhalides of the type lt, Brt,
etc.
li
ii)
Write the similarities shown by lithium and magnesium.
(4)
Ans :-
Lithium resembles magnesium in the following respects
(a) Both Li and Mg are harder and have higher melting points
(b) Li like Mg decomposes water slowly to liberate hydrogen.
2Li +2111o -#
2L'OH + H21
Mg + 2HzO -#
Mg(OH), + tt.1
(c) Both the elements combine with nitrogen on heating.
6Li+ Nz - 2Li3N
3Mg+11.+Mg3N2
Both the nitrides are decomposed by water with evolution of
ammonia(NH3).
(d) Both Liand
Mg combine with carbon on heating.
2Li+ 2C +Li2C2
Mg+2C+MgC2
Both the carbides yield CzHz with water.
(e) Lithium forms only monoxide when heated with oxygen.
Mg also forms the
monoxide.
4Li + Oz +2LizO
2Mg +O2 +2MgO
Both the oxides are less soluble in water.
(f) Hydroxides of Li and Mg are weak bases and.are slightly soluble in water.
Both decompose on heating.
2LiOH +Li2O
+
HzO
Mg(OH)2 +MgO +H2O
(g) Lithium fluoride, phosphate, oxalate and carbonate, like the conesponding
salts of Mg, are sparingly soluble in water.
(h) The bicarbonates of Li and Mg do not exist in solid state, they exist in
solutions only.
B
D
Mention any four uses of sodium carbonate.
Ans:- The main uses of sodium carbonate are as water softener, food
processing aid, pH modifier, swimming pool chemical and electrolyte. It
is also used in the manufacture of glass, paper, soaps and detergents,
and many other useful chemicals.
1.
lt is used as a water softener in laundering: it competes with the
maonesium and calcium ions in hard water and orevents them from
(4)
bonding with the detergen
carbonate can be used
to
4'
ase, oil. and wine stains.
ln china, it is used to replace lye-water in the crust of traditional
cantonese moon cakes, and in many other chinese steamed buns and
noodles.
5.
sodium carbonate is used by the brick industry as a wetting agent to
reduce the amount of water needed to extrude the clay.
6.
7
'
8.
In casting, it is refened to as "bonding agent" and is used to ailow
wet alqinateto adhere to gelled alginate.
sodium carbonate is used in toothpastes, where it acts as a foaming agent
and an abrasive, and to temporarily increase mouth pH.
Sodium carbonate is used by the cotton industry to neutralize the sulfuric
acid needed for acid delinting of tuzzy cottonseed.
restoring silver metal. The sulfide can
brine from brine
China is the world's
d at27O
million tonnes, the top five producers (in million tonnes) being china (60.0), United
States (45.0), Germany (16.5), India (15.8) and Canada (14.0). Satt is atso a
Properties
o It is easilygoluble inwater and partially or insoluble irr6ther liquids.
.
They are white crystals which do not have an odour but possess a taste.
a
OR
B
D
State anyfour uses ofsodium bicarbonate.
Ans :- Sodium bicarbonate, referred to as "baking soda", is primarily used in baking, as
a leavenino aqent. lt reacts with acidic components in batters, releasing carbon dioxide,
which causes expansion of the batter and forms the characteristic texture and grain in
pancakes, cakes, quick breads, soda bread, and other baked and fried foods. Acidic
compounds that induce this reaction include phosDhates, cream of taftar, lemon
iuice, voqurt, buttermilk, cocoa and vineoar. Natural acids in sourdough can be leavened with
the addition of small amounts as well. Sodium bicarbonate can be substituted for baf,i4g
powderprovided sufficient acid reagent is also added to the recipe. Many forms of baking
powder contain sodium bicarbonate combined with calcium acid phosphate, sodium
aluminium phosphate or cream of tartar.
Sodium bicarbonate was sometimes used in cooking vegetables, to make them softer,
although this has gone out of fashion, as most people now prefer firmer vegetables.
However, it is still used in Asian and Latin American cuisine to tenderise meats. Baking soda
may react with acids in food, including vitamin C (L-ascorbic acid). lt is also used in breading
such as for fried foods to enhance crispness and allow passages for steam to escape, so the
breading is not blown off during cooking.
By heating
Heat causes sodium bicarbonate to act as a raising agent by releasing carbon dioxide when
used in baking. The carbon dioxide production starts at temperatures above 80 'C.
2NaHCOg
+ NazCOe + HzO + COz
Since the reaction occurs slowly at room temperature, mixtures (cake batter, etc.) can be
allowed to stand without rising until they are heated in the oven.
Pest control
Used to kill cockroaches. Once consumed, it causes internal organs of cockroaches to burst
due to gas collection.
Paint and corrosion removal
Sodium bicarbonate is used in a process for removing paint and corrosion
called p!3!!4!!gg; the process is particularly suitable for cleaning aluminium panels which
can be distorted by othertypes ofabrasive.
Alkallnity/pH Increase
It can be administered to pools, spas, and garden ponds to raise the total alkalinity, this will
also raise the gfl level and make maintaining proper pH easier. In the event that the pH is
low and the alkalinity is adequate or high, Baking Soda (sodium bicarbonate) should not be
used to adjust the pH.
Pyrotechnics
Sodium bicarbonate is one of the main components of the common incendiarv "black
(4)
g[9" firework. The effect is caused by the therma
dioxide gas to produce a long snake-like ash as a c
component, sucrose.
Mlld dislnfectant
It has weak
organisms.
for used-bo
ve funqicide against some
it has become a reliable method
Fire extlngulsher
Sodium bicarbonate can be used to extinguish small grease or electrical fires by being
thrown over the fire, as heating of sodium bicarbonate releases carbon dioxide.
Neutrallsatlon of acids and bases
Sodium bicarbonate is amohoteric, reacting with acids and bases. lt reacts violently with
acids, releasing COz gas as a reaction product. lt is commonly used to neutralize unwanted
acid solutions or acid spills in chemical laboratories,
A wide variety of applications follows from its neutralisation properties, including reducing the
spread of white ohosohorusfrom incendiary bullets inside an afflicted soldier's wounds.
Medlcal uses
Sodium bicarbonate mixed with water can be used as an antacid to treat acid
indiqestion and heartbum.
Intravenous sodium bicarbonate is an aqueous solution that is sometimes used for cases
of acidosis, or when insufficient sodium or bicarbonate ions are in the blood. In cases of
respiratory acidosis, the infused bicarbonate ion drives the carbonic acid/bicarbonate buffer
of plasma to the left and, thus, raises the pH. lt is for this reason that sodium bicarbonate is
used in medically supervised cardiopulmonarv resuscitation. Infusion of bicarbonate is
indicated only when the blood pH is markedly (<7.1-7.0) low.
It is used for treatment of hvoerkalemia, as it will drive K* back into cells during periods of
acidosis. Since sodium bicarbonate can cause alkalosis, it is sometimes used to treat aspirin
overdoses. Aspirin requires an acidic environment for proper absorption, and the basic
environment diminishes aspirin absorption in the case of an overdose. Sodium bicarbonate
has also been used in the treatment of tricvclic antideoressant overdose. lt can also be
applied topically as a paste, with three parts baking soda to one part water, to relieve some
kinds of insect bites and stings (as well as accompanying swelling).
Sodium bicarbonate has been found to have no effect on the blood pressure ofseveral types
of rat models susceptible to salt-sensitive hvoertension, in contrast with sodium chloride. This
was ascribed to the high concentration of chloride, rather than the sodium content in dietary
salts.
Sodium bicarbonate can be used to treat an allergic reaction to plants such as ooison
!!ry, poison oak, or goison sumac to relieve some of the associated itching.
Bicarbonate of soda can also be useful in removing splinters from the skin.
Some altemative practitioners, such as Tullio Simoncini, have promoted baking soda as
a EIIEI cure, which the American Cancer Society has warned against due to both its
unproven effectiveness and potential danger in use.
Sodium bicarbonate can be added to local anaesthetics, to speed up the onsetoftheir
effects and make their injection less painful. lt is also a component of Moffett's solution,
used in nasal suroerv.
Personal hyglene
Toothoaste containing sodium bicarbonate has in several studies been shown to have a
better whitening and plaque removal effect than toothpastes without it.
Sodium bicarbonate i
and abrasive properties. rt works as a mechanical cleanser
on the teeth and gums,
neutralises the production of acid in the mouth, and also acts ai ,n-"niir"ffto
help prevent
infections.
sodium bicarbonate in combination with other ingredients can be used
to make a dry or
wet deodorant.
Sodi.um bicarbonate may be.usedas a buffering agent, combined
with table salt, when
creating a solution for nasal inioation
It is used in
bicarbonate
eyelash bas
s done by addition of a teaspoon of sodium
, followed UV genfle ;cruOoing ot tne
ution.
In sports
As a cleanlng agent
ounces (1 /0 g) of baKng soda in 2 gallons (7.5 l) of water.
As a biopesticide
b
the
Sodium bicarbonate can
States is registered by
ngal growth, and in the United
al a bispesg9ide.
Cattle feed supplements
Sodium bicarbonate is sold as a cattle feed supplement, in particular as a bufferinq aqent for
the rumen.
How is calcium oxide prepared
Ans:- Preparation
?
What are its properties ? (any two)
bl
it
react with COz from the air
lcium carbonate unless
a
Annual worldwide production of quicklime is around 283 million tonnes.
China is by far the
world's largest producer, with a total of around 170 million tonnes pei year.
ihe United
States is the next largest, with around 20 million tonnes per year.
o
than
limestone-is required per 1.0 t
a more efficient desiccant
d with an increase in volume by
high
icklime
Properties of calcium oxide
r,
Quick lime is an amolphous white solid with a high melting point of 26000
c
It is a very stable conrpound and withstands high temperatues,
t
rn the pr€sence of watero it forms slaked lirrre, This process is called slakins
of lime.
CaO+Il2O
'
It is
+
Ca(OI{)2
an oxide which is basic in nature and forms salts when
it comes in contact with an acid.
Formulate the hydroxides of alkaline earth metals and comp-re thEir
Ans :-Alkaline earth metals
-
formulation for their hydroxides.
biliilirengths,
M(oH)2 where M- alkaline earth metal is a general
In particular can be formutated as Be(OH)2, Mg(OH)2, S(OH)2, Ba(OH)2 and
Ra(oH),
Be(OH)2 is amphoteric, but the hydroxides of other alkaline earth metals are basic.
The basic strength increases gradually.
Thus, Mg(OH)z is the weakest base whereas Ba(OH)2 is strongest, The basic
character increases because as we move down the group the size of M2* ion
increases and hence the polarig of M-oH bond increases. As a result there is
higher ionisation from Mg(OH), to Ba(OH)2.
Be(OH), +
2HCl-
BeClz + 2HzO
Be(OH)2 + 2NaOH---+ Na2BeO2 + 2HzO
Sodium beryllate
The solubility of hydroxides increases with increase of atomic number of the
alkaline earth metals. This is due to the fact that decrease in lattice energy is more
than decrease in hydration energy on moving down the group.
What are the different types of o*
each with a suitable example
Ans:oxides.are binary compounds of oxygen with an erement ress erectronegative
than
oxygen itself.
e of this type than other alkali metals.
:'|i}ff;|iji
2Li2O
form peroxides. rhe peroxides are prepared by
+773KL!2O2+ 2yi
(iii) superoxides (Mo2) - The superoxides are obtained by heating
the peroxide
with oxygen under pressure except lithium and sodium, ttre remaiiinjalkali metals
form superoxides (KO2, RbO2, CsO2)
The above type of oxides readily react with water. They can be distinguished from
eech other by the products formed during their hydrolyiis reaction.
(Normaloxide)M2O + HzO
2MOH (no H2O2and 02)
-
(peroxides) M2O2 + 2H2O
+
(superoxide) 2MO2 + 2H2O
2MOH + HzOz ( HzOz and no 02)
+
2MOH + HzOz + Oz (both
H2O2
and 02)
a A
4
i)
+,!J
dn
at
",
Cnnrelt' P*}tmrnt tlh:rtrhre't
^.
A''I
r.
rJJ
.l
f,ncnfiornt'>S
av&
e
qJ
Q' P rods
d '*
:
^",
e6p1*,rof.in6
Jhn\ sys{*r*, o#
t'rs{"$
a'qr"'a is*,rq,r*.-r n
-;rrrcnclslurg' ,Is
afra
J
ftr
*Fd
TF in {htr
qYq.
}s \
flrs
geda .* rr*
*
strL
Frsalur
tg
$c"mrn{.t'
q'*e
al't$
ri.ts
H'*-+*
c.Rd
u
hq-rH
c*fxol+ elqg*
H
Thrqo
*-_dq*
B
D
rnh
I rrl
{$ialtrtol
erod iF ['}"lu
!*k-q.
['}lu ,$*k-c.
l{
i
hs
for
lf
n*d
{ e"r;rt*era Srvrpla
( fht{a eyrynrp:k
--
?# fl.I
irl
.t
o1
Ti
S s
xr,l-
vr.*-
,
&'"'"
^4? b ) _{ }e_
-# ts"
) "*i rl"> ip t*^.
n/^
.*.
,
e?
F
NF'")tu-;rrlc{})-1
*rr,*
J
6n*$3""ttd$f
-{h.,h
*R
S su. yn s
A
e-
e.
E*rch
s
ffr ut
}*d*o
"*'&
&
6"+
Syf
0'.
Suppose
lSfol
lthen
x) mol dm-3.
x mol dt"
the amount of the reactant left unreacted at time .t,
Then, the rate of reaction at time
't'
canbe given by the
will be (a_
equation-
#=K@-x)
WhereK-rateconstant.
On reananging the above equation, it becomes
dx
fr
= Kdt ...................O
On integrating the above equation
t:
0
and
.r
ffh=rc
:
0 to time t
:t
&x:
within limits
x
at start of the reaction when
Ilat
-ln(a - x) - [-ln(a
-
0)] = /( [r - 0]
1n o =6i
\4-x)
7a
:. K = -lnt---(a-x)
.'.
...
r(
=
2.303. a
_tog(;;,
The above equation is the integrated rate constant expression for a first order
reaction
low concentratio
quality-of plqnt
;xposed to SO2 for sufficient time
suffer from Chlorosis disease, i.e. bleaching or yellowish
of green
portions of the leaves.
oxyacids.of sulphur damage building materials such as lime
stone,
marble, slate, etc.
acid damages iron due to corrosive action.
p
Describe the metallic
non
"nO
to their variation across
the period and down the group.
AnS :-Metallic
and Non-metallic Character
tendency of an erement to rose erectrons qlrd form positive
ions (cations) is
called electroposrtive or metailrc character. ror exampL,
,Et"s are the
most electropositive elements.
"rr,"ii
Th_e
'The tendency of an element to accept electrons to form an anion is
called its nonmetallic or electronegafive character." For exampre, cnrorine, oxvgen
phosphorous show greater electronegative or non-metrallic
character]
'
ano
Across a period, metallic character of elements decreases as we
move to the right.
Conversely, non-metallic character increases from left to right.
left of the periodic table have a tendency of losing
o those to the right. As we move from left to right-of
outer shell experience greater pull of the nucleus.
j,i
:ili:
ize or th e ato m d ec rea,
r,.o
:i",Xfi ?il :
lXXi T: ?,i3l 3 lf"
". electrons eality
right of the table do not lose
^lf so are non-metallic in nature.
s
:
lL
n
"
As we move down the group metallic character increases.
Reason - the number of shells increases. This causes the effective nuclear charge
to decrease due to the outer shells being further away: in effect the atomic size
increases. The electrons of the outermost shell experience less nuclear attraction
and so can lose electrons easily thus showing increased metallic character.
Additional
e.g. In the third period, sodium on the extreme left is most metallic, The metallic
S.rdin$,ty
dA$*
i"sgt
."
A
od
L:l
U chirq.{ rrrolql
.'t
rJ ttl
rr p?ei
'---\'
-.f-t
Ir*K
dil
trirqlta
-
*t"J
L3J
I{
:
g$.rulcluil
$;
*
XXXXXXX&SXXXX