FISSION AND FUSION
BY :
SHAZIYA KHAN
BSC M.I.T (2nd SEMESTER )

HISTORY:
Hahn & Strassman
Meitner & Frisch
 In 1939 They First Identified the nuclear fission.
 Explained Hahn & Strassman results.
 Instead of heavier Uranium , it had split into smaller
elements = Nuclear Fission.
Their Statement Was :
 Bombarded Uranium -235 samples with neutrons expecting
the Uranium – 235 to capture neutrons.

A LITTLE BIT ON THE ATOM:

NUCLEAR FISSION
A reaction in which an atomic nucleus of
a radioactive element splits by
bombardment from an external source ,
with simultaneous release of large
amount of energy , used for electric
power generation.

CHAIN REACTION
 A chain reaction occurs when a
critical mass of uranium
undergoes fission .
 Releasing a large amount of heat
and energy that produces an
atomic explosion.

NUCLEAR FISSION DIAGRAM

ENERGY FROM FISSION
Each uranium-235 atom ha a mass of
3.9014 x 10-25 kg.
The total number of atom in 1kg of
uranium-235 can be found as follows:
No. of atoms in 1kg of uranium-235 =
1/3.9014 x 10-25 .
No. of atoms in 1kg of uranium-235 = 2.5 x
10-24 atom.

ENERGY FROM FISSION
If one uranium-235 atom undergoes a fission
reaction and release 2.385 x 10-11 J of energy , then
the amount of energy released by 1 kg of uranium-
235 aca be calculated as follows:
Total energy per fission x number of atoms
Total energy = 2.385 x 10-11x 2.56 x 1024
Total energy = 6.1056 x 10 13 J

NUCLEAR POWER PLANT
In nuclear power plants:
Fission is used to produces energy.
Control rods in the reactor absorb
neutrons to slow and control the
chain reactions of fission.

FISSION CAN BE USED:
 GOOD
A controlled chain reaction in a reactor used
in nuclear power plant to produce electricity.
 EVIL
An uncontrolled chain reaction is used to
create incredibly powerful weapons – the atomic
bombs dropped on Japan.

NUCLEAR FUSION
 Nuclear fusion is the process by which multiple
nuclei joins together to form a heavier nucleus.
 It is accompanied by the release or absorption of
energy depending on the masses of the nuclei
involved.
2H + 3H 4He + 1n + Energy
1 1 2 0

FUSION : SMALL NUCLEI FROM LARGER
NUCLIDE , RELEASE ENERGY

ENERGY FROM FUSION
2H + 3H 4He + 1n + Energy
1 1 2 0
m = 3.1 x 10-29 Kg E = mc2
C = 3x 108 ms-1 E = 3.1 x 10-29 x (3 x 108)2
E = E E = 2.79 x 10 -12 J
The energy released per fusion is 2.79 x 10-12 J.

FUSION CAN BE USED
 GOOD
A controlled reaction in a reactor used to
produce cleaner , inexpensive electricity.
 EVIL
A fission bomb starts a fusion chain reaction to
create an incredibly powerful weapon –
thermonuclear weapons (H-bombs), MUCH more
destructive than atomic bombs.

THANK
YOU