L6 : Non Metals - Metal & Non-Metal, Science, Class 8 Video Lecture

hello friends this video on metals and
nonmetals part 6 is brought to you by
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so now we have discussed about the
physical properties of metals we saw
that metals are malleable ductile
slowloris
with high density good conductors of
heat and electricity so now let us talk
about nonmetals so first we will start
with the definition of nonmetals so
these are those substances which has
electronegative in nature just the
opposite of metals so here they do not
have a tendency to lose electrons rather
they want to gain electrons so whenever
it is metals so you can see that metals
are like they move they believe in
giving so they release electrons whereas
nonmetals they are the takers they want
to take electrons so they will gain
electrons so examples of nonmetals are
carbon sulfur iodine oxygen hydrogen now
if you see most of the nonmetals they
are either solids or gases however there
are exceptions to non metals which are
liquid for example bromine soap roaming
is one such nonmetal which is liquid so
in non metals what happens is inside the
atom inside that substance you have seen
number of electrons and protons but in
this case they want to get additional
electrons so additional electron comes
in and therefore overall the substance
becomes electronegative in nature
because there are gold negatively
charged particles so here if you see the
since it has taken
additional electrons winds taking
additional negative charge so obviously
overall charge will become negative and
that is why they are electronegative in
nature so these are nonmetals so I have
already explained you what what what
does it mean about to take electrons or
to release electrons now the question is
why do we study nonmetals where do we
use them now again the uses of nonmetals
are also huge we actually cannot survive
without them so if you think of
nonmetals if you think of the gases like
oxygen and carbon dioxide so you see
that living organisms survive due to the
presence of oxygen and carbon dioxide
and oxygen and carbon dioxide these are
all gone metals carbon dioxide is made
up of carbon and oxygen so carbon is
also a nonmetal oxygen is also a
nonmetal you look at the plants plants
take in carbon dioxide during the
process of photosynthesis and they give
out oxygen
now without these two gases plants can
survive and this oxygen again is taken
in by the animals including me human
beings and we give out carbon dioxide so
these nonmetals help us to survive the
survival of life depends on the
existence of these nonmetals not only
that if you look at the rockets the
combustion of fuel needs oxygen so
oxygen again is a nonmetal you look at
the composition of air air contains 78%
of nitrogen it contains 21% of oxygen so
nitrogen oxygen carbon dioxide argon all
these nonmetals together form them air
around us so not only this if you see
these gases like nitrogen and oxygen
carbon dioxide they not only form that
cause fear nitrogen is also very very
important for the growth and development
of trunks apart from that we also have
fuels which are excellent sources of
energy for
example cool so what is coal coal is
made up of carbon and what is carbon
carbon is of course a nonmetal so core
is again of an excellent fuel excellent
source of energy and we have already
studied in our previous lesson that
there are so many different uses of coal
again if you talk about diamond it is
again made up of carbon it is in fact it
is one form of carbon and the diamond is
used for making a lot of jewelry's
graphite which is present in the
batteries or the pencil needs so that is
that also contains carbon which is again
a nonmetal the neon lights which you see
on in the shops or in the disks or even
in the streets so these neon lights are
also made up of neon which is again a
nonmetal in fact there are nonmetals
like hydrogen and helium which are
present inside balloons the gas balloons
which just cook when you leave it it
just goes up high in the air so it
contains hydrogen helium so they are
also nonmetals you would have also seen
that in the swimming pools now swimming
pools contain so much of water there so
there are chances that infection or the
water gets dirty do it because there are
so many organisms insects and everything
inside the water so therefore you would
have seen that chlorine is applied in
swimming pools for keeping away
infection so what is chlorine fluorine
is again a nonmetal so all these
chlorine neon hydrogen helium carbon so
these are all examples of nonmetals
not only that in fact lawn metals are
also used in a lot of antiseptics for
example iodine
yes the same iodine which is present in
salt the iodized salt so iodine is also
useful in preparation of a lot of
antiseptics
that's how we see that even nonmetals
are also I mean used in our day-to-day
life in fact forget about day-to-day
life we are surviving due to the
presence of these nonmetals like oxygen
carbon nitrogen life-forms would not
exist without these so it is equally
important to talk and to discuss about
nonmetals as well so again in a very
similar way here also we will start with
the history of nonmetals
well nonmetals we're the only nonmetal
which was discovered during the
prehistoric time was carbon now that is
quite surprising right do you remember
when we talked about the history of
metals we saw that gold was the first
one to be discovered in 6000 BC but gold
was not the only one there were many
other metals like copper iron which were
discovered during the BCS so during the
prehistoric time a lot of metals got
discovered but compared to that only
carbon was the only nonmetal which was
discovered during the BCS and that to
carbon was discovered in the form of
coal now one reason behind this is when
you talk about metals they are not
solids so that you can actually see them
so discovering them is easier when
compared to these non metals which are
mostly in the gaseous form so you really
cannot just imagine that ok carbon is
present here oxygen is present here or
nitrogen is present here because they
are in gaseous form it is little
difficult to find to them or to prove
their existence but however over period
of time gradually other nonmetals were
also discovered the next one to be
discovered was phosphorus which was
during the 13th century so there was a
long gap between the discovery of carbon
and phosphorous
now when phosphorus was discovered it
was mostly used in explosives while it
was used in explosive because of its
reactive nature so we will talk about on
that next was oxygen which was in 1774
so you see oxygen is
something which is so much important
right like oxygen is present in our
atmosphere the air is composed of almost
21 percent of oxygen in fact the entire
Earth has almost 50 percent oxygen
because when you talk about the oceans
oceans contain one water what it is
hydrogen and oxygen so oxygen being such
an important element on earth it was
discovered very recently because 1774 is
not very I met not long ago so it was
discovered quite recently then gradually
all other nonmetals were discovered like
nitrogen chlorine sulfur hydrogen and so
on so that's how the nonmetals were
gradually discovered another interesting
thing if you compare metals with
nonmetals is that if you look at the
number of metals they are more when
compared to the number of nonmetals
so in nonmetals you have comparatively
lesser number of elements when compared
to the number of metal so quantity 1 so
that means the number of metals and
number of non metals metals win but when
you look at the amount of metals on the
amount of non metals which are found on
earth then of course nonmetals win
because the quantity of nonmetals is
definitely more on the earth you talk
about oxygen you talk about nitrogen you
talk about God and they are all present
in huge amount on the earth oceans are
hydrogen oxygen atmosphere have nitrogen
oxygen carbon so that that means the
existence or the quantity of nonmetals
is more on the earth yet compared to
metals but when you look at the elements
how many of them are metals and how many
of them are nonmetals you see that there
are more metals than non metals thank
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