A laboratory record shows a nucleus containing 18 protons and 24 neutrons after a neutron was emitted and the daughter nucleus then underwent beta-minus decay.
The possible parent nuclei are listed.
| Candidate nucleus | Number of protons | Number of neutrons |
|---|---|---|
| P | 17 | 26 |
| Q | 17 | 25 |
| R | 18 | 25 |
| S | 19 | 24 |
Which candidate was the parent nucleus?
Nucleus R
Nucleus Q
Nucleus P
Nucleus S