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CLASS 6 SCIENCE SEPARATION OF SUBSTANCES

PURE SUBSTANCE- A pure substance is has particles o one !in" onl#$

or e%a&ple- "istille" 'ater contains particles o 'ater onl#$

(I)TURE- (i%ture is a co&bination o t'o or &ore t#pes o particles$or e%a&ple -air has particles o o%#*en + nitro*en + carbon "io%i"e +'ater in the or&

o ,apour $ ust an" s&o!e particles are also present in air$

The substances present in a &i%ture are calle" its co&ponents so o%#*en+ nitro*en+

carbon "io%i"e+ 'ater in the or& o ,apour+ "ust an" s&o!e particles are the

co&ponents o air$

./0 O .E NEE TO SEPARATE (I)TURES1

2$ TO RE(O3E /AR(FUL CO(PONENTS-

e*$ So&eti&es rice or pulses &i*ht contain s&all stones 'hich can be

har&ul or us4$ TO RE(O3E UNESIRABLE SUBSTANCES5CO(PONENTS-

E*- So&e !i"s "ont li!e nuts in pu""in*+ so the# separate the& ro& it

E*- So&e chil"ren separate 7&alai ro& &il! as the# "ont li!e its taste$

8$ TO OBTAIN USEFUL CO(PONENTS-

E*- Petroleu& is reine" to separate petrol+ 9erosene+ "iesel an" 3aseline

etc as petroleu& cannot be use" as such$

E*- Crea& or butter is separate" ro& &il!$

E*- Salt is separate" ro& sea 'ater$

:$ TO ;ET PURE SUBSTANCE FRO( A (I)TURE-

E*- istille" e is re&o,e" ro&

the &i%ture b# han"$

This &etho" can be use" 'hen the co&ponents o the &i%ture "ier in si>e+

shape or colour an" 'hen the co&ponent to be separate" ro& the &i%ture ispresent in s&all ?uantit#$

For e%a&ple- stones can be re&o,e" ro& rice b# han"pic!in*$

- Corian"er lea,es can be separate" ro& &int lea,es b# han"pic!in*

Li&itations o han"pic!in*-

- this &etho" cannot be use" 'hen co&ponents o &i%ture are ,er#

s&all in si>e

- this &etho" beco&es ,er# ti&e consu&in* 'hen the &i%ture to be

separate" is in lar*e ?uantit#

SIE3IN;-

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This &etho" is use" 'hen a &i%ture has particles of different sizesan" a

sie,e can be use" to separate the&$

the pores in the sie,e 'ill allo' the s&aller particles o the &i%ture to pass

throu*h the& an" retain the particles 'hich are bi**er in si>e$

E*- - separatin* bran ro& the 'heat lour$

- separatin* stones ro& san" at construction sites

T/RES/IN;-

In this &etho"+ a 'ea!l# attache" co&ponent is separate" ro& the

re&ainin* part b# *i,in* a su""en thrust5orce< b# beatin*+ sha!in* etc=

E*- *rains are separate" ro& their stal!s b# threshin*$

- "ust is separate" ro& carpet5oot&at b# sha!in* it or beatin* it

a*ainst a har" surace$

.INNO.IN;-

In this &etho"+ lighter componentsare separate" ro& heavier componentsb# blo'in* air or wind.

For e%a&ple- cha is separate" ro& the *rains b# 'inno'in* as cha is

li*hter than the *rains$ The &i%ture o cha an" *rains is &a"e to all ro& a

hei*ht$ ;rains are hea,ier an" all "o'n al&ost ,erticall# an" the li*hter cha

'ill be blo'n a'a# b# the 'in" an" or& a heap at a "istance$

(A;NETIC SEPARATION-

In this &etho"+ a &a*netic co&ponent is separate" ro& non &a*netic

co&ponent b# usin* a &a*net$

E*- iron nails can be separate" ro& sa' "ust b# usin* a &a*net$

T/IN9 AN ANS.ER-

2$ .hich &etho" shoul" be use" to separate-

e$ .ill sie,in* be a suitable &etho" to separate these re" an" 'hite

bea"s1 ;i,e reason or #our ans'er$

:$ The ollo'in* i*ure sho's separation o stones ro& san" at a

construction site$ Na&e the &etho" o separation$ Also *i,e reason that

'h# are stones re?uire" to be separate" ro& san" or construction

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