Question

Describe the processes that take place inside the nucleus for the following decays; Beta- decay and Beta+ decay.

Answer 1

Step-by-step explanation:

(a) Electron Emission (Beta- decay):

When an unstable nucleus decays by the emission of Beta- particle, its charge number ‘Z’ increases by 1 but, its mass number ‘A’ remains unchanged. The transformation is represented by the equation:

`_zX^A\ -------->\ _(Z+1)Y^A\ +\ _(-1)e^0`

It is called ‘Negative Beta Decay’. It is more common than alpha decay.

Example:

`_6C^(14)\ -------->\ _(7)N^(14)\ +\ _(-1)e^0`

Note:

There are no electrons in a nucleus so, with the emission of a particle, one of the neutrons is converted to a proton and an electron.

`_0n^1\ --------->\ _1P^1\ +\ _(-1)e^0`

(b) Positron Emission (Beta+ decay):

When an unstable nucleus decays by the emission of the positron, its charge number ‘Z’ decreases by 1 but, its mass number ‘A’ remains unchanged. The transformation is represented by the equation:

`_zX^A\ -------->\ _(Z-1)Y^A\ +\ _(+1)e^0`

Examples:

`_(15)P^(30)\ -------->\ _(14)Si^(30)\ +\ _(+1)e^0`

Note:

Inside the nucleus, only a proton can be transformed into a neutron with the emission of a positron (anti-particle of electron)

`_1P^1\ -------->\ _0n^1\ +\ _(+1)e^0`