Question

A common example of \(\beta ^{-}\) decay is
\({}_{15}\text{P}^{32}\longrightarrow {}_{16}\text{S}^{32}+x+y\)
Then x and y , respectively, stand for

• A. positron and anti - neutrino
• B. electron and neutrino
• C. electron and anti-neutrino
• D. positron and neutrino

Hint:

In beta minus decay a neutron changes to a proton, emitting an electron and an antineutrino.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept
In \(\beta^{-}\) decay a neutron changes into a proton: \(n\rightarrow p+e^{-}+\bar{\nu}\).

Step 2: Balance Mass and Charge
The mass number stays 32 and the atomic number rises from 15 to 16, so one electron (charge \(-1\)) is emitted to balance charge.

Step 3: Lepton Number
The electron has lepton number \(+1\), so the other particle must carry \(-1\), which is an antineutrino.

Step 4: Conclusion
So x is an electron and y is an anti-neutrino.

Final Answer:
The decay emits an electron and an anti-neutrino. \[ \boxed{\text{(C) }\text{electron and anti-neutrino}} \]