Answer :
The original particle that decays to produce neon-21 and a positron is sodium-22.
Here's how the decay process occurs:
1. A sodium-22 isotope undergoes radioactive decay.
2. During the decay process, sodium-22 transforms into neon-21 and emits a positron.
3. The positron is the antimatter counterpart of an electron and has a positive charge.
Therefore, in this radioactive decay scenario, the original particle is sodium-22, which transforms into neon-21 and releases a positron.
