The correct statement that describes why the expression is incorrect is:
A neutron should be expressed as \( ^1_0n \), not \( ^1_1n \).
This indicates that it was incorrectly labeled as \( ^0_1n \) instead of the correct representation, which is \( ^1_0n \). In this notation, the superscript represents the mass number (1 for a neutron), and the subscript represents the charge (0 for a neutron). The expression you provided appears to reverse the usual notation for a neutron.