An unidentified parent nucleus undergoes beta-minus decay. The daughter nucleus contains 16 protons and 16 neutrons.
The table shows four possible compositions for the parent nucleus.
| nucleus | number of protons | number of neutrons |
|---|---|---|
| P | 15 | 17 |
| Q | 16 | 16 |
| R | 17 | 15 |
| S | 15 | 16 |
Which nucleus in the table was the parent nucleus?
nucleus P
nucleus R
nucleus Q
nucleus S