Trends in Group - 17 Elements (part - 1) Video Lecture - NEET

hello friends this video on p-block part
40 is brought you by exam fear calm no
more fear from exam let's start with the
electronic configuration is in tone the
reason why all these elements are in
group 17 years because they have a
common electronic configuration pattern
that is ns-two mp5 if you talk about
fluorine the electronic and
configuration is 1s2 2s2 2p5 2 plus 2
plus 5 is 9 this is 9 correct so if you
see this is the pattern n is 2 NP v n is
2 NP fine
alright you talk about chlorine also if
you see it is 3s2 3p5 bromine also for s
2 4 peopIe already know so 5 X 2 pi P 5
this also success to 6 people so they
have an electron a common electronic
configuration but one thing to note here
is which we have seen in other groups
also fluorine there is no D orbital no D
orbital in case of fluorine but chlorine
if you see since it is 3 so 3 third
shell will have a D orbital also right
and the fourth one off this is empty D
orbital chlorine has a MTD orbits C
flowing there is no D orbital chlorine
has IMPD orbital bromine has one
friendly orbital and when I am video
arbiter also here you'll have my 4 D 0
also so the good part about the
different fluorine other elements is
fluorine is not having any D orbital but
others has D orbital and we'll see that
this small difference will have a huge
impact on the properties of fluid and we
will see that fluorine has special
properties why because it is not having
any empty D orbital chlorine has a MP d
arbitral bromine has 1finity orbital or
empty D orbital in fact I didn't also
has one filled D orbital and there are
two filled orbitals
and one named 3d orbital so let's ignore
the empty in the field but just see that
fluorine doesn't have any D orbital but
chlorine bromine iodine astatine and
other member of the group 17 elements
have B orbital ok the next train which
will discusses the atomic and ionic the
next trend will go for as the atomic and
ionic radii so the covalent radius on
the right hand side dying akkadian that
I didn't say if you see if you talk
about the covalent radius it increase
from if you go from top to bottom
fluorine is the smallest then chlorine
size increased then bromine size
increased and then iodine sides or the
pony great
you talk about the ionic radii also that
also follow follows a similar pattern
there's a gradual increase in the radio
as you go from top to bottom
why because you end up increasing extra
shell the number of shells increase
number of increase due to increase in
the number of shells the atomic size
increase n this is the same even as we
have seen in other crops nothing special
about it ok but one thing to note is
they have smaller radii in the
respective period you talk about a given
period this period example you have
sodium here right these if you don't put
one period they have smaller radii why
because the max effective nuclear charge
is nuclear charge is more effective if
you drop what a given period and then
they have a smaller smallish radii
actually the respective p in a given
period they have smallest
already called atomic radii so for
example if you talk about one period
let's take a second period you have
lithium beryllium boron carbon nitrogen
sorry nitrogen oxygen fluorine neon so
in this period if you go from left to
right the size decrease and the fluorine
will be smaller size smaller size the
new one will be a little bigger they are
noble gas
so in fluorine the effective nuclear
charge is maximum you know atom's
nucleus okay so please note this is my
group 17 so group 17 it has smallest
atomic radii in a given period to take
about a given pH all let's take if you
take a second period for example you
talk about sodium and magnesium silicon
phosphorus sulfur chlorine right so
these guys will see will have smallest
this chlorine will have smallest size in
this period okay let's talk about
density now see the density actually it
increase down the group why see density
it was density is mass by water if we go
down the growth the volume is increasing
and mass is awesome
both are increasing but the mass is
increasing at a higher rate see if you
see this slide here the increase
in the radius is from 64 to 99 $64.99 1
1 4 1 3 3 let's put the valve 64 99 101
3 hey so this is my radius so increase
in radius for example here if you see is
how much from 64 to 99 is almost
increase of 35 right that's almost 50
percent increase and then from 99 to 114
there is almost 15 percent increase and
from 1 at 14 233 almost and almost 15
percent increased but if you talk about
the increase in mass right the mass is 9
to 17 almost hundred percent increase by
90% in 9 to 7 almost hundred percent
increase 735 almost again hundred-person
increase 35 to 53 or wash me deeper
single so if you see the increase in the
mass is almost 100% from fluorine to
chlorine but the increase in volume is
almost 50 percent so this guy mass is
increasing at a higher rate volume is
increasing at a lower rate correct same
same thing from chlorine to bromine if
you go the increase in my mass is almost
double but the increase in volume is
only 15 percent so the density is
nothing but mass by volume this increase
is more the single is less so overall
the density will increase and thus the
density has increased from one point six
six gram per centimeter cube to three
point one nine gram per centimeter all
right so since density is mass per
volume and in that trend we have seen
that the increase in mass as we go down
the room this is the higher rate on one
hundred thousand hundred possible but
the increase in volume is not at a very
high rate only the first one was the
t-boz an increase and then 15% increase
and thus if you see in the first case
fluorine to chlorine the density
increase also not that much but after
that the density increases more from
22nd dynasty is going to mass by volume
so since I know the trend in mass I know
their training volume I can easily find
that and in density and we already know
that the training mass is almost as
increase every time you happen from one
step to another step going to on the
blue and the increase in volume is not
that much the density increase actually
is there okay simple maths the next is
the time in the melting and boiling
point so we see the trend is pretty
obvious the melting point increased on
the blue the boiling point also
increased down the okay why because of
increase in the intermolecular force of
attraction that is a Warner work force
so with increasing the molecular mass
the maunder wall for business eyes also
molecule force increased and does the
melting point in the boiling point
increase this is very small core
including this bigger and thus if you
see there is a big jump from fluorine to
chlorine but after that there is almost
15 percent increase in the volume atomic
science so there's a grid increasing the
melting and boiling point and thus if
you see fluorine is a gas actually
chlorine is also a gas bromine is a
liquid an idea that is solid and these
are mocking board and - TV standard
temperature and pressure
fluorine crowing is my ass booming is a
liquid and iodine is a sorry
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