Question

What is the difference between positron emission and electron emission?

Answer 1

Positron emission and electron emission are the types of beta-decay, when the positron is emitted then the formed nucleus has one less atomic number than the old one, while when an electron is emitted then the formed nucleus has one greater atomic number than the old nucleus.

Complete answer:
We know that the higher nucleus is converted into a smaller nucleus by emitting radiations in the form of helium atoms, electrons, neutrons, positrons, etc. causing alpha-decay, beta-decay, gamma-decay, etc.
Positron emission and electron emission are the types of beta-decay, when the positron is emitted then the formed nucleus has one less atomic number than the old one, while when an electron is emitted then the formed nucleus has one greater atomic number than the old nucleus.
So, when the nucleus emits an electron or a neutron then is known as beta-decay ($\beta -decay$).
When the electron is emitted then it is known as negative beta-decay and it is represented as ${{\beta }^{-}}$ decay. An example of electron emission or negative beta-decay is the conversion of carbon-6 to nitrogen-7. The reaction is given below:
$_{6}^{14}C\to _{7}^{14}C+_{-1}^{0}e$
Here we can see that the atomic number is increasing by one.
When the positron is emitted then it is known as positive beta-decay and it is represented as ${{\beta }^{+}}$ decay. An example of positron emission or positive beta-decay is the conversion of magnesium-23 to sodium-23. The reaction is given below:
$_{12}^{23}Mg\to _{11}^{23}Na+_{1}^{0}e$
Here we can see that the atomic number is decreased by one.

Note:
In both the emissions, there is only a change in the atomic number of the element or atom but the mass number will remain the same. Positron is also known as a positive electron.