A materials technician analyses the nuclei of atoms in an alloy sample.
The results are shown in the table.
| Nucleus | Mass number | Number of neutrons |
|---|---|---|
| S | 52 | 28 |
| T | 54 | 30 |
| U | 54 | 28 |
Which statement identifies the correct relationship between the nuclei?
T and U are isotopes, and S contains two fewer protons than either of them.
S and T are isotopes, and U contains two fewer protons than either of them.
S and U are isotopes, and T contains two more protons than either of them.
S and T are isotopes, and U contains two more protons than either of them.