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1. WELCOME

2. POWER POINT
PRESENTATION
BY
ANUPARVATHY A
PHYSICAL SCIENCE
EMMANUEL COLLEGE
OF
B.ED TRAINING

3. FUNDAMENTAL CONSTITUENTS
OF SUBSTANCE –ATOM

4. RECALL……….
• MOLECULES IS THE SMALLEST PARTICLE OF A PURE
SUBSTANCE
• MOLECULES ARE MADE UP OF SMALLER COMPONENTS
CALLED ATOM
• IN THE MOLECULES OF A SUBSTANCE, IF THERE ARE
ONLY TYPE OF ATOMS, THEN THAT SUBSTANCE IS
CALLED AN ELEMENT
• SUBSTANCE MADE OF ATOMS OF DIFFERENT
ELEMENTS ARE COMPOUNDS.

5. ATOM
• THE BASIC UNIT OF ALL SUBSTANCES.
THE WORD ‘ATOM' ORIGINATED FROM
LATIN WORD ‘ATOMOS’ WHICH MEANS
“THAT CANNOT BE DIVIDED
• THE ANCIENT GREEKS WANTED TO
LEARN ABOUT THE SMALLEST PARTICLE
OF MATTER.
DEMOCRITUS
ARISTOTLE

6. DEMOCRITUS
• BELIEVED THAT ALL MATTER CONSISTED OF EXTREMELY SMALL
PARTICLES THAT COULD NOT BE DIVIDED.
• HE CALLED THERE PARTICLES ATOM
ARISTOTLE
• HE DID NOT THINK THERE WAS A LIMIT TO THE NUMBER OF
TIMER MATTER COULD BE DIVIDED
• HE THOUGHT THAT ALL SUBSTANCE WERE BUILT UP FROM
ONLY FOUR ELEMENTS.
• EARTH, AIR, FIRE, WATER

7. IS ATOM DIVISIBLE ………..?
DALTON’S THEORY SAYS ‘NO’.
INVESTIGATION INTO THE STRUCTURE OF MATTER LED THEM TO
THE ATOMIC THEORY.

8. JOHN DALTON
• THE PROPOUNDER OF ATOMIC THEORY
IN MODERN PERIOD.
• THE ATOMIC THEORY PUT FORWARD
BY JOHN DALTON IN 1808 WON THE
RECOGNITION FOR THE ATOM AS A
FUNDAMENTAL CHEMICAL PARTICLE.

9. POSTULATES OF DALTON’S
ATOMIC THEORY
• ALL MATTER IS MADE UP OF SMALL PARTICLES CALLED
ATOMS.
• ATOM IS THE SMALLEST PARTICLE WHICH CAN ENGAGE
IN A CHEMICAL REACTION.
• ALL ATOMS OF AN ELEMENT HAVE THE SAME PROPERTIES
THAT IS THEY HAVE SAME MASS, SIZE AND CHARACTER.
• ATOMS OF DIFFERENT ELEMENT HAVE DIFFERENT
CHARACTERISTICS
• ATOMS CAN NEITHER BE CREATED NOR DESTROYED
• ATOMS ARE INDIVISIBLE.

10. THANK YOU