Question

multiple-choice question
the best way to identify an unknown chemical or substance is by
asking a friend
directly smelling the chemical/substance
reading the label
tasting a small sample of the chemical/substance

Explanation:

Para identificar un químico desconocido, "Asking a friend" no es fiable. "Directly smelling" o "Tasting" pueden ser peligrosos (p.ej., sustancias tóxicas). "Reading the label" es seguro y proporciona información precisa del producto.

Answer:

C. Reading the label