The document summarizes the development of the periodic table over time. It describes Dobereiner's Law of Triads, Newland's Law of Octaves, and Mendeleev's and Moseley's contributions which established that an element's properties are determined by its atomic number rather than atomic mass. The modern periodic table is arranged into seven periods and eighteen groups and classifies elements as metals, nonmetals, and noble gases based on their electronic configurations.

1. PERIODIC TABLE
Genesis of Periodic
Classification of Elements!

2. STEPWISE DEVELOPMENT OF PERIODIC
TABLE
Dobereiner’s Law of Triads
Newland’s Law of Octaves
Mendeleev’s Old Periodic
Law
Moseley’s Modern Periodic
Law

3. DOBEREINER’S LAW OF TRIADS
 In each group of three members called triads,
the middle element had an atomic weight about
half way between the atomic weights of the
other two

4. NEWLAND’S LAW OF OCTAVES
The arrangement of the elements in
increasing order of their atomic weights and
noted that every eighth element had
properties similar to the first element
The relationship was just like every eighth
note that resembles the first in octaves of
music.

5. NEWLAND’S TABLE
This study awarded Davy medal

6. MENDELEEV’S OLD PERIODIC LAW
 Mendeleev’s Law (Old periodic law)
states that “The properties of the
elements are a periodic function of their
atomic weights”
 Mendeleev predicted the existence and
properties of some elements and his
prediction was absolutely correct
 He called the groups as “columns” and
periods as “series”

7. MOSELEY’S MODERN PERIODIC LAW
 Modern Periodic Law states that “The
properties of the elements are a periodic
function of their atomic numbers”
 He said that the properties of every
elements varies with atomic number not
with atomic mass
 The modern periodic table is in
accordance with modern periodic law

8. LONG FORM OF PERIODIC TABLE
 Periodic table consists of seven periods numbered from 1
to 7 and the 7th period is still incomplete
 Periodic table consists of eighteen groups numbered
from 1 to 18
 Pure metals are placed on left hand side and non metals
on the right hand side
 Hydrogen finds a separate and unique position in the
periodic table because its property does not match with
any other elements
 Periodic table is divided into four main blocks depending
upon where the last electron enters namely s-, p-, d- or f-blocks
 The liquid metal present in periodic table is mercury (Hg)
and the liquid non metal is bromine (Br)

9. LATIN NAME FOR SOME ELEMENTS
Sodium – Natrium (Na)
Potassium – Kalium (K)
Mercury – Hydrargyrum (Hg)
Silver – Argentum (Ag)
Gold – Aurum (Au)
Tin – Stannum (Sn)
Lead – Plumbum (Pb)

10. THE END!

11. PRESENTED BY
NITHYA S NAIR
Physical Science
Badriya College
Velichakkala
Kollam

12. THANK YOU