Dobereiner's Triads Video Lecture - Class 10

hi in the session of periodic
classification of elements we are going
to understand the concept of Tauber
Aeneas trials now in earlier times many
elements have been discovered with more
and more elements being discovered the
scientists went on gathering lots of
information about their physical and the
chemical properties now because there
was lots of information there arose a
need to classify the newly discovered
elements into groups a german chemist
named Johan Wolfgang dobrynya came up
with this idea to classify the elements
which have similar properties into
clusters of three now these clusters of
three were known as tribes now since
this was dobrynia
idea to classify these elements into
trials this type of classification is
known as java rainiest trials now that
we know what adopted rainiest rides let
us go ahead and study the DA brainiest
law of tribes the law states that when
elements were arranged in order of their
increasing atomic mass the atomic mass
of the middle element was approximately
the arithmetic mean of the other two
elements of the tribe let us take a look
at the three top Irenaeus tribes in this
table given below the first tried is
lithium sodium and potassium
the second tribe is calcium strontium
barium and the third tried is chlorine
bromine and iodine
let us first concentrate on the first
tried that is lithium sodium and
potassium here the atomic mass of
lithium is 7 the atomic mass of sodium
is 23 and that of potassium is 39 by
applying Dubliners law of trials we get
the mean of the atomic mass of the first
and the third elements to be that is the
atomic mass of lithium and potassium to
be 7 plus 39 upon 2 that becomes 23 now
as you can see the atomic mass of the
middle element that is sodium is also 23
thus we can say the table Rania's law of
trials is applicable to the first tribes
similarly let us apply this law to the
second tribe that is calcium drawn
shrimp and barium here the atomic mass
of calcium is 40 John Simm is 88 and
barium is 137 again by applying
Davinia's law of tribes we get the mean
of the atomic masses of the first and
the third element that is calcium and
barium to be 40 + 137 upon 2 so that
becomes 88.5 which again is
approximately equal to the atomic mass
of the middle element ron shipp
similarly the double Rania's law of
trial is also applicable to the last
tribe that is chlorine bromine and
iodine again by applying the arena's law
of triads we get the mean of the atomic
mass of the first and the third element
that is chlorine and iodine to be 35.5
plus 1 27 upon 2 which equals to 80 1.5
which again is a
proximately equal to the atomic mass of
the middle element bromine da brainiest
Riots was not very successful as it had
few limitations the first and the major
limitation was that many elements having
similar properties could not fit into
the tribe let us take for example nickel
manganese copper magnesium iron they all
have similar properties but they could
not be placed in the tribe the second
disadvantage was that elements having
dissimilar properties were placed in the
tribe the third and the major
disadvantage was that dobrynya was only
successful in classifying
three tribes now since dobrynia strides
could not be applied to the then-known
elements this method of classification
was not very successful I am sure your
understood the concept of dobrynia
strides to watch more such videos please
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