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1. welcome

2. The first attempt to clarify the
elements was made by the French
scientist: - ANTOINE LAVOSIERE
IN 1789
He classified the 33 elements in
to 4 groups
17 metals
6 nonmetals
5 gases
5 earth metals

3. John Dalton formulated a new
theory called atomic theory in 1808.
He found that atoms of each
elements have a fixed masses, through
they are small in 1808.He found that
atoms of each elements have a fixed
mass, through they are small.

5. Doberenier classified
elements into groups of
three on the basis of
similarities of properties.
He named these groups as
triads.

6. He arranged the elements in
the ascending order of atomic
masses.
He proposed the
LAW OF OCTAVES

7. He arranged the elements in
the ascending order of
atomic masses . Plotted
atomic weight against
atomic volume

8. He published a table of the
elements in the increasing order
of atomic mass.
It provided a scientific
foundation for the systematic
study of chemistry. He published
the famous periodic law

9. He proposed Modern periodic
law .
He modified periodic table
on the basis of increasing
order of atomic number.

10. Metal Reaction with water Reaction
with
dilute
acid
Melting
point
Density
Sodium Vigorous reaction producing
Hydrogen
Vigorous
reaction
producing
hydrogen
98ºC 0.97g/
cm³
Iron No reaction with cold water Slow
reaction
producing
hydrogen
1537ºC 7.87g/
cm³
Silver No reaction No
reaction
962ºC 10.5g/
cm³
Potassium Vigorous reaction producing
hydrogen
Vigorous
reaction
producing
hydrogen
64ºC 0.86g/
cm³
Zinc No observable reaction Moderate
reaction
producing
hydrogen
419ºC 7.1g/
cm³