Question

Signature of
Teacher
Remarks
CHEMISTRY
Chaptes-s
are classified by
physical properties
PERIODIC CLASSLEICATION OF ELEMENTS
Tobics to cover :-
Need for classification, early attempts at classification of
elements [Dobereiner's trinds, Newland's law of Octanes,
Mendeleev's Periodic table. J. Modern beriodic table", gradation
in probenties, valency, atomic number, Metallic and
non-metallic properties.
INTRODUCTION:-
At present
elements are known.
oln the year 1800 only 30 elements are known.
CLASSIFICATION OF ELEMENTS :-
classification of elements
on the basis of
factors such as
density, malleability duckility, etc.es and also
to consider whether they were metals of non-metals),
what is the need for classification of elements?
NEED FOR CLASSIFICATION :-
olt helps in studing the elements in
organised manner.
olt helps in Correlating the properties of
elements with the fundamen dal properties of all states of
matter.
olt helps in defining the relationship of
one element with another.
Doberliner's triads : xyz + 2+2 = 4
• Jow. Dobereind, a German chemit
obseaused that certain elements displayed similar properties and that
they could be placed in groups of 3 elements each
2 why was
doberian's triad discarded
an​

Answer 1

Answer:

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