In a radioactive decay of a nucleus, an electron is also emitted. This may happen due to the fact that :

The correct answer is 2.

Key Points

• Beta Decay is a type of radioactive decay in which a proton is transformed into a neutron or vice versa inside the nucleus of the radioactive sample.
• While doing so, the nucleus emits a beta particle which can either be an electron or positron. Hence, option 2 is correct.
• The beta decay occurs via the weak interaction.
• Beta particle (β) are high energy, high-speed electrons or positrons that are ejected from the nucleus during beta-decay.

Additional Information

• Alpha Decay – The radioactive decay in which the ejected particle is an alpha particle.
• Gamma Decay – A radioactive nucleus first decays by the emission of an α or β particle.