John Dalton proposed that all matter is made up of small indivisible particles called atoms. Atoms of different elements have the same properties but different masses. Atoms cannot be created or destroyed. J.J. Thomson's experiments showed that atoms emit invisible rays and negatively charged particles. Rutherford's gold foil experiment revealed that atoms have a small, dense, positively charged nucleus surrounded by electrons distributed in empty space.

3. NAME : LEKSHMI PRIYA R
REG.NO : 18214384007
OPTION : PHYSICAL SCIENCE

5. JOHN DALTON’S
POSTULATES OF ATOM

6. • All matter is made up of small
particles called atoms
•Atom is the smallest particle
which can engage in a chemical
reaction•Atoms of different elements
have same properties
•Atoms are indivisible
•All the atom of an element have
the same properties. That is, they
have the same mass, size and
character•Atoms can neither be created nor
be destroyed

7. .INFERENCES ARRIVED BY
SIR.J.J.THOMSON

8. The cause of the glow is the
invisible rays emitted from the
negative metal plate
It is the flow of particles with
negative charge
There are particles carrying
negative charge in all substances

9. RUTHERFORD’S GOLD FOIL
EXPERIMENT

10. Electrons are distributed in the space
around the nucleus
Atom has a central part , called Nucleus
Nucleus has positive charge
The mass of an atom is concentrated in
the nucleus