Question

In ${\beta ^ + }$ decay process, the following changes take place inside the nucleus
A. ${}_Z^AX \to {}_{Z - 1}^AX + {e^ + } + \gamma$
B. ${}_Z^AX \to {}_{Z + 1}^AX + {e^ - } + \gamma$
C. ${}_Z^AX \to {}_Z^AX + {e^ - } + \gamma$
D. ${}_Z^AX \to {}_{Z - 1}^AX + {e^ + } + \bar \gamma$

Answer 1

Beta decay is a form of radioactive decay, and positive beta decay is one of the types of beta decay in which the proton in the nucleus of a radioactive sample disintegrates into neutrons or vice-versa.

Complete step by step answer:
The decay of beta particles is done in such a way that the proton and neutron have an optimum ratio. In the process of achieving an optimum ratio, a beta particle is emitted from the nucleus, and this emitted beta particle could be positive or negative. Hence, beta decay can be divided into units; ${\beta ^ + }$ decay or positron emission and electron emission.

In the process of ${\beta ^ + }$ decay, a proton in the nucleus of a radioactive sample is changed to a neutron which emits a neutrino of electron and a positron. This position is a positive particle, and its mass is the same as an ordinary electron, but it has the opposite charge. For a positron emission mass number is the same but the number of atoms decreases by one as a result of which it forms a difference.

Hence, in positron emission, a daughter nucleus is produced, which has the atomic number one less than the parent nucleus, and the mass number is the same. Thus, we can write the equation as below:
${}_Z^AX \to {}_{Z - 1}^AX + {e^ + } + \gamma$

Therefore, based on the above explanation, we can say that the proton inside the nucleus decays to get converted into a neutron, and option (A) is the correct answer.

Note: Do not get confused between positive beta decay and negative beta decay because $\beta$ only represents the emission of electrons from nuclei, but this electron emission could be positively charged or negatively charged.