Question

How is it possible for a positively charged nucleus to release a negatively charged beta particle?

Answer 1

Hint: The positive charge of a nucleus results due to release of electrons from the outer shell and not from the nucleus. The beta decay is the release of electrons from the nucleus as the unstable nucleus needs to gain stability.

Complete step by step answer:
The nucleus of an atom is composed of protons and neutrons. Both are collectively called nucleons. The protons are positively charged species and the neutrons are neutral species having no charge.
A nucleus becomes positively charged in two ways. The first one is due to the removal of electrons from an atom which leads to more number of protons in the nucleus as hence the nucleus becomes positively charged.
The second way is related to the subject of radioactive emission. In this case an unstable nucleus undergoes radioactive decay either by itself or by attack by a fast moving neutron leads to release of electrons in the form of beta decay.
As a result the neutrons are converted into protons by the release of electrons and the nucleus becomes positively charged.
As for example let us consider the higher isotope of carbon i.e. carbon-\[14\]. Carbon-\[14\] is an isotope of carbon -\[12\]. Carbon-\[14\] has \[6\] protons and \[8\] neutrons. Due to more number of neutrons than protons in the nucleus the nuclear stability is disturbed.
This causes one of the neutrons undergoing a beta decay thereby releasing an electron and becoming a proton. The beta decay and release of an electron results in \[7\] protons and \[7\] neutrons and so the nucleus becomes nitrogen \[14\] which is a very stable atom.

Note: The nucleus contains both positively charged protons as well as neutrons with both positive and negative charges. The bombardment of nucleus by high energy neutrons causes radioactive decay and leads to formation of smaller stable nuclei.