Characteristics of alpha
(
α
)
(
particles
a
.
a
Nature
:
:
An alpha particle is a helium atom from which two electrons have been removed.
b
.
b
Mass and charge
:
:
An alpha particle has a mass of
4
a
μ
4
and a charge of
+
2
+
units. Therefore, symbol of an alpha particle is
.
2
H
e
4
.
. ltbr.
c
.
c
Speed
:
:
Alpha particles have a low speed of upto
10
%
10
of the speed of light. ltbr.
d
.
d
Penetrating power
:
:
These ray can penetrate an aluminium sheet of
0.002
c
m
0.002
thickness.
e
.
e
Effect of electric field
:
:
Alpha particles are positively charged and are deflected strongely by an electrostatic field.
Characteristics of beta
(
β
)
(
particles ltbr.
a
.
a
Nature
:
:
These rays are made up of stream of electrons.
b
.
b
Mass and charge
:
:
The mass of a beta particle is
1
/
1840
a
m
u
1
and the charge of a beta particle is
−
1
-
unit. The mass of a beta particle is so small that it is taken to be zero in the nuclear reactioins. The symbol of the beta particles is
.
−
1
e
0
.
c
.
c
Speed
:
:
The speed of beta particles is
90
%
90
of the speed of light and
10
10
times that of
α
−
α
particles.
d
.
d
Penetrating power
:
:
They can penetrate an aluminium sheet of upto
0.2
c
m
0.2
thickness.
e
.
e
Effect of electric field
:
:
They are heavily deflected by an electrostatic field because of their relatively smaller momentum compared to
α
−
α
rays.
Charactersitics of gamms
(
γ
)
(
rays
a
.
a
Nature
:
:
Gamma rays are electro
−
-
magentic radiations with a very short wavelength of the order of
10
±
10
.
b
.
b
Mass and charge
:
:
Gamma rays have no mass and no charge. A gamma ray is represented by the symbol
.
0
γ
0
.
. ltbr.
c
.
c
Speed
:
:
Gamma rays travel with the speed of light.
d
.
d
Penetrating power
:
:
Gamma rays can penetrate upto
100
c
m
100
thick aluminium sheet.
e
.
e
Effect of electric field
:
:
Gamma rays are not deflected by an electrostatic field because of the absence of charge and mass associated with them.
