Nuclear fission Nuclear fusion Nuclear Fusion

. Splitting of a heavy nucleus into two or more lighter

nuclei.
e.g : 92U + 0n
235 1
56
Ba141 + 36 Kr92 + 3 0n1 + 200Mev
NUCLEI . Combining two lighter nuclei to form a heavy nucleus.
1
1H
1
+1H →
2
1H +e
+
+v +0.42 ( energy )
Application
. Uncontrolled chain reaction: principle of atomic bank. Nuclear Nuclear fussion is the source of energy in the sun and stars.
. Contralled chain reation: principle of nuclear reactors.
Fusion
Nuclear of an atom onsists of proton and
Nuclear Fission neutrons collectively called nucleons. Nuclei can be

. Isotopes (same Z but different A)

Representation . Isobars (same A but different Z)
. Isotones (same N but different A) discoverd by henri
Becquerel in 1896
zxA
A = mass number
z = Atomic number

Radio activity
Nuclear Force theory
. Nuclear force is a force which
holds the nucleons together. Phenomenon of Disintegrakon
of heavy elements into
n
comparatively lighter elements
Rodius of a nucleus by emission of α, β, & γ radiations.
R = R0A1/3 { R0 = 1-2fm}
Binding Energy of Nucleus
. Density of Nucleus (S)
⇒ B .E = mc 2
⇒ B .E = [zmp + (A - Z ) m n - m n ]c 2 Mass Mass of 1 nucleon × A α decay β− decay γ decay
=
Volume 4 1 . α− radiations are the two types
(Where, c is the speed of light πR 3 = π R 03A z
3 2 helium nuclei. These γ -decay after an α or β
c = 3 × 108 m/sec)
. Nuclear density is constant its . For atomic number < 20, most are emitted as β (positron)
+
β (Electrons)
-
- decay, nucleus vibrates
B .E value is nearly 2.38 × 1017 kg/m3 stable nuclei have n:p ratio with the energy shared
⇒ B .E per nucleon = AX→ 0 β + Az + 1 Y + υ
No . of nucleons nearly 1:1 A
zX → 4
2 He + zA-4
−2 Y
z −1 ↓ by it and electromagnetic
. Mass of nucleus is measured . For atomic number > 83, there (electron) (antineutrina) waves of very high
Nuclear binding energy is maximum for α-particle
in atomic mass unit (u) or (amu) are no stable nuclei. (Product) frequency (α-radition) are
mass number 50-60. Daughter emitted
1 amu (or u) = 1/12 (mass of C12) atom . A nucleus is stable when its A
→ +01 β + zA− 1 Y + υ
nuclei z X
= 1.6 × 10-27 kg Binding energy per nucleus (nutrino)
(Position)
value is around 8 mev per . highest ionizing power . least ionizing power but
nucleon or more. but least penetrating . less ionizing power than α highest penetrating power.
. Mass defect
. Following are observations from power. . particle and moderate
The difference (∆m) between mars of
Binding energy per penetrating power.
constituent nucleons and nucleus is
called mass defect of nucleus. nucleon versus mass number cerve.
Mass and energy [∆m = sum of the masles of nucleons
. Mass m of a particle is equivalent ∆Ebn
- mass of nucleus]
to energy given by E = mc2 Law of radio activity
= {zmp + (A - Z)mn} – Mn
. Also known as rest mass energy.
− dN
4He = λN
dt
7Li N = N 0e - λ t
mean life or any life
Q-Value
56 z 1 T 1/2
A + B C + D + Energy τ = = =1.44T 1/2
MA MB mC mD λ 0.693
. B.E. per nucleon is more for some
Fraction of nuclei left
Reactants = product + Q- Value nuclei than their neighbours.
undcayed after n half
Q value = B.E of product - B.E. OF reactants This indicates a shell type structure
Half - life lives is
Q-value = [(mA + mB) - (mC + mD)] C2 of nucleus. t decay rate or activity
N N  1
N
 1 t1 2
Q-value = [(k.EC + k.ED) -(K.EA + K.EB)] . B.E. per nucleon is around 8meV where N = 0 =   =   dN
FOR 30 ∠A ∠120, these are 2 N0  2  2 R= -
dt
stable elements. ln 2 0.693
T1 = = Where, t = nT1/2
2 λ λ R = λ N0 e- λt or R = R 0 e - λt

anand_mani16 DR. Anand Mani https://www.anandmani.com/ https://discord.io/anandmani t.me/anandmani001