PPT: Structure of the Atom | Science Class 9 PDF Download

 Page 1


STRUCTURE OF
Page 2


STRUCTURE OF
C O N T E N T S
Atomic Structure
1
Models of Atom
2
Atomic Number and
Atomic Mass Number
4
Valency
3
Isotopes and Isobars
5
Page 3


STRUCTURE OF
C O N T E N T S
Atomic Structure
1
Models of Atom
2
Atomic Number and
Atomic Mass Number
4
Valency
3
Isotopes and Isobars
5
The structure of an atom
comprises protons
(Discovered by E.
Goldstein), neutrons
(Discovered by Chadwick)
and electrons ( Discovered
by J.J Thomson)
These basic components
provide the mass and
charge of the atoms. 
STRUCTURE OF ATOM
Page 4


STRUCTURE OF
C O N T E N T S
Atomic Structure
1
Models of Atom
2
Atomic Number and
Atomic Mass Number
4
Valency
3
Isotopes and Isobars
5
The structure of an atom
comprises protons
(Discovered by E.
Goldstein), neutrons
(Discovered by Chadwick)
and electrons ( Discovered
by J.J Thomson)
These basic components
provide the mass and
charge of the atoms. 
STRUCTURE OF ATOM
STRUCTURE OF ATOM
Electrons have
Negative Charge
Neutrons have No
Charge
Protons have
Positive Charge
Page 5


STRUCTURE OF
C O N T E N T S
Atomic Structure
1
Models of Atom
2
Atomic Number and
Atomic Mass Number
4
Valency
3
Isotopes and Isobars
5
The structure of an atom
comprises protons
(Discovered by E.
Goldstein), neutrons
(Discovered by Chadwick)
and electrons ( Discovered
by J.J Thomson)
These basic components
provide the mass and
charge of the atoms. 
STRUCTURE OF ATOM
STRUCTURE OF ATOM
Electrons have
Negative Charge
Neutrons have No
Charge
Protons have
Positive Charge
According to this theory, atoms are like plum
pudding, with tiny positive charges scattered
throughout a cloud of negative electrons. This
theory helped explain why atoms have a
neutral charge overall and why they emit light
when they collide with each other.
Couldn’t explain why electrons didn’t
collapse into the positive sphere
Failed to predict the distribution and
arrangement of electrons
Lacked explanation for the nucleus and its
positive charge
L I M IT A T I O N S
THOMSON'S
MODEL OF
AN ATOM