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, neutrons
and electrons. 
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, neutrons
and electrons. 
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, neutrons
and electrons. 
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
LIM ITATIO NS
THOMSON'S
MODEL OF
AN ATOM