In a radioactive decay process, the negatively charged emitted β-particles are

47 2007 AIPMT-PRE NucleiBeta Decay Easy
In a radioactive decay process, the negatively charged emitted $\beta$-particles are
A the electrons produced as a result of the decay of neutrons inside the nucleus
B the electrons produced as a result of collisions between atoms
C the electrons orbiting around the nucleus
D the electrons present inside the nucleus

Detailed Solution

A nucleus contains only protons and neutrons; there are no electrons present inside the nucleus.
In beta minus decay ($\beta^-$), a neutron inside the nucleus is transformed into a proton, and an electron is emitted from the nucleus along with an antineutrino.
$n \rightarrow p + e^- + \bar{\nu}$
The electron is created at the instant of the decay and is ejected immediately; this emitted electron is the $\beta^-$ particle.
As a result the atomic number increases by one while the mass number remains the same.
The orbital electrons and collisions between atoms have nothing to do with this nuclear process.
So the $\beta$-particles are the electrons produced as a result of the decay of neutrons inside the nucleus.

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