Final answer:
SnCl₃⁻ is an ion, specifically a negatively charged anion composed of tin and chlorine atoms with an extra electron resulting in a negative charge.
Step-by-step explanation:
SnCl₃⁻ is an ion, specifically a negatively charged ion known as an anion. It consists of one tin (Sn) atom and three chlorine (Cl) atoms, with an additional electron to give it a negative charge, resulting in a charge of -1. Hence, SnCl₃⁻ is not a neutral element, a molecule, or none of the above; rather, it is correctly identified as an ion. This kind of species is often present in ionic compounds, which are formed from the electrostatic attraction between cations and anions.