Mendeleev periodic table - Elements & Periodicity Video Lecture - Class 11

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understand the mentally predictable the
the best periodic table I can say the
best effort so this guy what I did was
he arranged their immense based on their
fundamental problem systemic mass now
also base for the chemical property but
chemical property was given the first
prior so at that time there were 63
animals known so he his work was on this
63 elements he first tried to find the
relation with atomic mass and the
chemical and physical property and to
find the chemical properties
relationship he selected the hydrogen
oxygen as because they were very
reactive and they formed compounds with
motion element so they he reacted most
of element with hydrogen and oxygen and
the way it react with hydrogen oxygen
example this is somebody's X and it
reacted with hydrogen it gives something
an X we have oxygen it get something
right it may be our n may be X H may be
x h2 right maybe in this case maybe Expo
it can give X 2 or it can give think so
- right it can give X 2 O 3 based
operation of the poverty of the element
right so it can react in different ways
so similarly with hydrogen also can
react in different ways you can give X X
3 is x h4 so based on the reaction of
the element hydrogen oxygen he grouped
the elements correct and then he also
used the atomic mass to arrange them
correct so at a in the formula of
hydrides in the oxide vichy gate the
hydrogen oxide small Alicia gate was one
of the critical parameter for cross
section element so what he did was
actually four he took for example 63
elements I Ito 63 cards in each of this
card he lowered this element named
resemble the element
X and this guy formed some headlight
6-inch and some oxide x coordinates of
the right and atomic masses that suppose
in 58 minutes in Z so this guy he agreed
cars like this you need 63 cards like
this with all the 53 elements named and
all the hydrides and oxides and all the
atomic mass once he had all these values
right he know all the 63 year events
name you know the atomic mass of all
this humans he knows the hydrates the
oxides form now he group these elements
based on these hydrogen oxide they are
the critical thing yet see you see the
last one the newline love active he
arranged beach on the atomic masks alone
right so his his his parameter was
atomic mass and then he found that they
have some rectangular on it but this guy
for him the critical thing is chemical
property and then he he's trying to
arrange the atomic mass right and if he
finds a missing object he has created
two gaps also in the tables they explain
that but let's understand that both have
a different approach the Newlands one
what it was his his primary concern was
the increasing atomic mass and then he
found that coincidentally they have
repetitive chemical property for this
guy the critical or the main thing was
it should have same properties chemical
property than this the kind of hydrogen
oxide form should be similar and then
the second critical thing was up atomic
mass alright so he started this elements
based on the similar properties and also
of that most of the elements got a place
in the periodic table to be arranged in
the order of atomic mass increasing
atomic mass so he was able to arrange
them correct and he also observed the
periodic recurrence of elements with
similar physical and chemical that's
what what Newlands have observed he also
observed here also correct and in for on
basis of all this experiment he did he
he gave a periodic law right and you say
that the property of the elements
a periodic function on the enemy path
this is the law he gave this law is
called mental aspheric law it says that
property of the elements are purely
function of atomic mass please note it's
atomic mass we don't need the atomic
number now because atomic number is not
even discovered by this time then
because the electrodes was not
discovered all the atomic mass which we
use hair is all found by it the chemical
reactions because the base of all this
was the Dalton theory don't - we gave
this Turing 1804 very told the mass can
either be created not going to destroy
that stick you mentor equations they
found the chemists form a lot of atomic
masses and these was the atomic mass was
used by Mendeley I hope it is clear to
you so what he has done was he reacted
these elements with hydrogen oxide he
found different hydrides different
oxides and based on the hydrogen oxide
found he co-opted these elements right
and then he arranged this elements based
on the increasing atomic mass keeping in
mind that all this form which forms
simpler hydride oxides are in a similar
group education with that I think it'll
be more clear example if you see the
hydrates can be are to open instead of X
they are using are here or ro R - o 3r o
- R 2 O 5 r o3 r 2 O 7 and are over the
different kinds of hydride he found and
then the clump or these elements right
and then hide the oxides for hydrides
are h h2 or h3 or h4 RS three RS 2 or H
these were the hydrates so based on
these two we cops example for these
combination he found usually invents say
Club all these into one group correct
all this into one go all the money so he
he grouped elements like this correct
and then if you see he he called his
vertical columns has two so this guy's
girl groups so Group one group
to group three and these were all
periods may they all be the he called
this use this word groups infinitely
share also used in the modern periodic
table so with this if you see everything
an atomic mass here hydrogen atomic mass
and then if you see there's a lithium
beryllium boron carbon nitrogen oxygen
fluorine all the atomic mass right
envision the properties this is what the
kind of periodic table he formed which
was pretty good
very very few limited intact but was
very good actually
so we'll explain the merits and demerits
of these periodic table so let us do
this hope you understand how he found
the spirit table so let's understand the
achievement of this mentholated table
first thing is related sound elements
which are not discovered at that time
because when he arranged the elements he
found that some elements of are missing
because some of the elements atomic
possible missing and then he gets it he
gets that okay there will be atomic
element which will be found in your
future we should have atomic mass of 68
and he called that guy as a car
aluminium because it used found
equilibrium and that element was found
in future and we call it 11 that element
has kali and he also what he will guess
the formula of oxides in chlorides if
you see he guessed that that particular
element which will have a formula of e 2
o 3 based on his periodic table and
that's what it was
he also gives the formula of chlorides
or hydride to be like this that is e CL
3 and we found in gallium also follow
the same sciutto he guessed the
existence of sun element mission on the
sky the time not only the existence of
the element but also the physical not
physical chemical property on the
elements he could predict properties of
several elements based or they pushed as
I told these elements right I mean they
were elements for mister poverty was
form but piece of the tradition you
could tell of if this guy will form
hydrates in this fashion
this guy will form oxides in this
fashion so in because if you see his
periodic table is all based on the
oxides and hydrates right you see the
way it is fall so example this guy he is
not reacted he don't know how it reacts
but just because this guy is in Group
four seven he can say that this guy will
form oxide like this it will be PR two
seven and will form hydrides like this
the edge so that's what the the purpose
is right so in this case let's suppose
it's very difficult to react this guy
with oxygen at that point of time so
what he don't okay I don't know how to
react but but I know that this guy la
will react with oxygen will form
something like la 2 O 3 and then this
guy reacts with hydrogen forms will be
like elastic and that was true also if
you react those things in chemistry lab
and you see that that was the kind of
reaction go through right so so with
just by looking at the position of the
element for example TI so 10 if react
with oxygen if it reacts it will form TI
m2 and it reacts in failure in poverty i
actually the way kind of things he was
able to tell just by looking at the
position of the element in the periodic
table also he could accommodate normal
gas because these gases were discovered
at that time only so once he has done
with the table after that the noble
gases where this court but he was able
to accommodate that so his table was
able to equivalent that there was one
good thing about his Stephen thank you
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