Magnetic Properties of Transition Metals (part - 2) Video Lecture - NEET

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talk about the magnetic properties so
minor big property we know is mostly
because of unpaired electrons in this
atom so this atom has a lot of electrons
and sometimes you have unpaired
electrons will see the scenarios and
that create this magnetic property in
this planet is used in speakers mostly
and if you see the type of mind we have
paramagnetic diamagnetic ferromagnetic
anti ferromagnetic ferromagnetic but we
will be discussing more about the
paramagnetic and diamagnetic
so in Dai magnetic it is repelled by
applied electric field and paramagnetic
is attracted by applied electric field
is paramagnetic is actually attracted by
applied electric field and diamond ring
is repelled by applying liquid okay so
in paramagnetic in diamagnetic Ashlee
all electrons are paired electrons it
okay and paramagnetic we have unpaired
electron since we have unpaired electron
they attract are they attracted towards
the electric field in diamagnetic all
the electrons are paired so they are not
attracted toward the electric field in
fact they are repelled by the electric
field okay and in fact there is
something called ferromagnetic also
ferromagnetic is nothing but glorified
version of paramagnetic glorified
version of parliment here they are very
strongly attracted by the magnetic field
and they have permanent magnetic moments
so in fact Ferro magnetism is I will say
extreme case of paramagnetism so will
not discuss that in fact the meaning of
the transition metals are
you know transition metals are
paramagnetic why because of the presence
of unpaired electron okay so we'll see
this paramagnetic so they told para
magnetism is nothing but you do unpaired
electron and they're attractive example
you see see this particular element is
being attracted by the magnetic field
right so they are attracted by electric
field as I told transition metals has
most of the transition metals has
unpaired electron and thus most of the
transition metals are paramagnetic most
TM TM is transition metals they are
paramagnetic right now each unpaired
electron has a magnetic moment T I'll
tell you what is paramagnetic for
example let us take manganese the
electronic configuration is 3 5 4 s 2 so
we draw the structure 1 1 2 3 4 5 s 1 2
3 4 5 indie and chewiness so we see this
is paired this is unpaired there 5
unpaired electron talk about titanium 3
D 2 4 s q4 s has 2 electron this D has 5
sorry D has 2 also so this has 2
unpaired electron again if we talk about
this suppose of da for nickel nickel is
3 D 8 or s 2 so 1 2 3 4 5 plus 1 2 3 4 5
6 7 8 right and SS 2 electron if you see
they are 2 unpaired electron here they
are 2 unpaired electron there 5 unpaired
electron so you'll see most of the
transition metal has unpaired electrons
and s they are paramagnetic now each of
these unpaired electron each of these
electron has magnetic moment associated
with its spin angular momentum also
and orbital angular momentum because
these actually electrons they spin like
this and they move water like this
so both the spin and the angular
momentum that the spin angular momentum
and the orbital angular momentum
both these Ashley has a magnetic moment
okay
so magnetic moment due to your orbital
angular momentum is not much to do the
movement is not much but it is mostly
due to the spin I'm talking about the
first system the first series scandium
titanium vanadium chromium to zinc Rahim
with the first series
so first is my magnetic moment due to
orbital angular momentum is not much you
know that right so we'll talk about only
the magnetic moment due to spin angular
momentum so you just think of a ball
when you throw a ball when you spin it
the ball Duvall's and it moves also same
thing this electron the revolve also
here like this and they also move just
like earth earth has been also and it
actually rotates also integrates and
Duvall's similar to that we have the
electron also rotates and revolves okay
so the orbital momentum is almost
negligible but yeah the spin momentum
has values and actually if you want you
can find the value of the magnetic
moment by a formula U is equal to n into
n plus 2 okay when n is the number of
electrons and this unit is B M that is
Bohr Magneton it is magnetic moment to
do spin off unpaired electron this mu is
magnetic moment due to spin the angular
movement okay
at the dole diamagnet substance the one
which doesn't have any unpaired
electrons Inc is one example of
transition metal which has no unpaired
electron you see the electronic
configuration of chain 3 D 10 for s to
draw this one two three four five one
two three five six see the doesn't have
any unpaid electron so jink is
diamagnetic Ferro magnetism is a strong
form of para magnetism an island
actually shows arrow mechanism will not
discuss much into this now we'll see
some of the binding properties if you
see a single unpaired electron mu is
equal to root of n into n plus 2 input
the values here 1 into 1 plus 2 that is
root of 3 that is 1.73 2 more Nandanam
so single unpaired electron produces a
magnetic moment of 1.73 Bohr Magneton ok
so if you increase the number of unread
electron the muon so increased so mu is
directly proportional to unpaired
electrons okay so actually the observed
magnetic moment that you can actually
observe this gives a useful data about
the number of unpaired electron example
you see the calculated value observed
value are all matching for most of these
ok so it gives a fair idea of how the
electron is how many are the atom is how
many unplayed electron it has okay and
if you see here also we have a trend it
increased from left to right if you go
from scandium titanium vanadium chromium
magnesium iron cobalt nickel copper zinc
so it increases right and then decreases
we see the current value also it
increases maximum here and then again
decreases why because
you talk about the number of unpaired
electron we have seen that it increases
and then it decreases you have seen that
right same thing so since the mind thing
moment is dependent on the unpaired
electron the unpaired electron increase
and the decrease in a given series so
the magnetic moment also increase and
then decrease in a given series okay
let's see some of the important
compounds example fe 3 plus n su 2 plus
and both are paramagnetic but fe 2 3
plus if you see the wanting all
electronic configuration fe 3 plus will
be 3d 5 4 s 0 fe 2 plus will be 3 d6 por
su so this has 4 unpaired electrons this
has 5 unpaired electron how you can see
okay 3 D 5 in Fe 3 plus it has 5
unpaired electron talk about equity 2
plus 3 6 1 2 3 4 5 & 6
it has 4 unpaired electron okay so the
number of our bait electrons actually is
more energy 3 plus so every three pluses
more paramagnetic than Fe 2 plus
similarly if we talk about Cu 2 plus Cu
2 plus is actually parama annex u 2 plus
if you see the electronic configuration
is 3 D 9 4 s 0 it has 4 unpaired
electron but if you talk about Cu plus
this is 3 D 10 4 s 0 and this is diamond
Cu plus s die by knitting but Cu 2 plus
is paramagnetic okay so it is not only
that always copper Billy paramagnetic or
I will be quorum for magnetic so this is
again for a given ion you have to find
the electronic configuration find number
of
unpaid electron and then you can
actually make out or confirm whether
it's a paramagnetic or diamagnetic we'll
take some numerical normal the first
question is the calculate the magnetic
moment of a divalent iron that is some
iron in the aqueous solution if the
atomic number is 23 so item ik number is
23 so for this it will be 35 so for m
class that M 2 class then it will be 23
subtract 2 okay so let's write the
electronic configuration for first for
this or 23 number 1s2 2s2 2p6 3s2 3p6 3
d 5 4 s 0 ok first write the electronic
configuration of M past this 25 25 is 2
4 6 10 12 18 and to 2025 this is the
electronic configuration of M 25 okay 3
5 4 s 2 that is my mynah knees so we
talked about off M 2 plus now it will be
1s2 2s2 2p6 3s2 3p6 3 d 5 4 s 0 the
electrons are take a plug from the 4 s
orbitals ok this is the electronic
configuration so let's find the number
of unpaired electron 3 D 5 1 5 1 2 3 4 5
right so this has 5 unpaired electron
since it is 5 unpaired electron the
magnetic moment is root dot n into n
plus 2 put the value is 5 that is 2.5
into 5 plus 2 that is 5 into 7 235 the
value is five point nine two or nine dot
okay so please first find the electronic
envision or given metal and then
the electronic configuration of the
given metal ion and make sure that you
plug electrons from the S orbital
outermost assortment calculate the
spin-only magnetic moment or m2 plus
where Z is equal to 27 again Z is equal
to 27 we can actually write as argon are
going to take care of 18 then my 4s to
20 rest will be in 3d 3d sir this will
be the electronic configuration of z 27
now we'll talk about M 2 plus ions so
the electronic configuration will be 3 B
7 4 s 0 / goes to electrons milli
platform flow at zero 4s orbital so
let's find the unpaired electron is 3 D
orbital 3 D 7 1 2 3 4 5 6 7 so number of
unpaired electron unpaired unpaired
electron is 1 2 3 M 3 so mu is what
through Talk n into n plus 2 root of the
value of n is 3 3 2 3 plus 2 that is
root of 3 5 15 and that is nothing but
almost 4 9 0 less than 4 3 point 9
almost this is a value okay thank you
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