Hand Picking Video Lecture | Science Class 6

hello friends this video on separation
of substances part 3 is brought to you
by exam for calm no more fear from exam
now the question is how do we separate
now there can be many types of mixtures
so you can talk about the mixture of
salt and water you can talk about a
mixture of sugar and water you can talk
about a mixture of milk and water you
can talk about a mixture of sale
rice grains and pebbles even talk about
a mixture of sand and salt so you can
think of hell lot of mixtures now since
different mixtures consist of different
types of components there are different
methods of separation for different
types of mixtures based on the
properties of the components based on
what kind of mixture is that now some of
the common methods of separation which
we will learn here are hand picking
threshing winnowing sieving
sedimentation decantation filtration
evaporation and condensation so these
are the methods that we will focus here
so for each method we will see what kind
of substances do the separate and we
will also look at the pros and cons of
each of these methods so let's start
with hand picking the name itself
defines it hand picking so we are
picking up things with our hand so
removing substances from a mixture with
hand so it is a core manual process and
it is going to be time-consuming because
that you are giving us let's say about
full of pulses and now you have to pick
the undesirable particles out of them so
you see here the yellow colored things
are the undesirable stuff so every each
single undesirable particle needs to be
picked up by you so it is definitely
going to be time consuming and also
being a manual process it is boring and
it is a tiring job but the hand picking
acts as a a wonderful method when you
have when the number of substances which
need to be removed is very less because
you just cannot do this for hours after
hours and days after days you cannot
repeat this for that long right so the
advantages of hand picking is that it
effectively removes big particles
because you are manually removing it so
once removed it means that you are
completely sure that yes I have removed
it so it is no more there but the
disadvantage is that it can remove big
particles but when it comes to small
particles let's see if I tell you that
let's say some powdery substance from
something like salt hat is there in a
mixture and you have to hand pick the
particles of salt will you be able to do
it no because the particles are
extremely tiny so you cannot even locate
where those particles are so if the
particle size is very small so so hand
picking doesn't work so it doesn't work
for tiny particles
second is being a manual process it is
very time-consuming so it takes a lot of
time so if it is helpful only when the
particles which you want to separate
they are comparatively bigger in size
secondly if the particles which you want
to separate they are smaller in quantity
so that the process doesn't take that
long so that's about hang tricky so it
is one of the very basic processes of
separating substances from a mixture
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