SRI VIDYADHIRAJA MODEL COLLEGE

OF TEACHER EDUCATION

NAME : LEKSHMI

PRIYA R

REG.NO : 18214384007

OPTION : PHYSICAL

SCIENCE

STRUCTURE OF

ATOM

JOHN DALTON’S POSTULATES OF ATOM

• 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

.INFERENCES ARRIVED BY

SIR.J.J.THOMSON

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

RUTHERFORD’S GOLD FOIL EXPERIMENT

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