The word 碰到 is formed by combining two characters: 碰, which means "to touch" or "to bump into" in a physical sense, and 到, a particle that often indicates arrival at or achievement of a result. Their combination conceptually extends the literal idea of physical contact into the abstract realm of experience, creating a unified meaning of "to encounter" or "to come across". It essentially marries the action (碰) with the notion of that action reaching its point of occurrence or completion (到), thus figuratively capturing the moment of an unexpected or chance meeting with a person, thing, or situation.