Radioactive nuclei emit `beta^-1` particles.
Electrons exist inside the nucleus.

Radioactive nuclei emit beta^- particles. Electrons exist inside the nucleus.

Assertion :Radioactive nuclei emit beta^-1 particles. Reason :Electrons exist inside the nucleus.

Assertion: Radioactive nuclei emit beta particles. Reason: electron exist inside the nucleus.

The electrons cannot exist inside the nucleus because

A radioactive nucleus emits beta particle. The parent and daughter nuclei are

A radioactive nucleus emits a beta particle. The parent and daughter nuclei are:

Explain,how radioactive nuclei can emit beta- particles even though nuclei do not contain these particles.Hence explain why the mass number of a radioactive nuclide does not charge during beta decay.