The Spanish word 'talio' comes from the English word 'thallium', which refers to the chemical element. Thallium was named using the Greek word 'thallos' (θαλλός), meaning 'green shoot' or 'branch', combined with the Latin-derived suffix '-ium' commonly used for chemical elements. The element got this name because when it was discovered in 1861, it showed a bright green line in its spectral analysis, reminiscent of new plant growth.

There aren't many common Spanish words directly related to 'talio' since it's a relatively modern scientific term derived from Greek. Most related Spanish words would be other chemical element names that share the '-io' ending (which corresponds to English '-ium'), such as 'sodio' (sodium) or 'calcio' (calcium).

The English cognate 'thallium' is the most direct relative, being the source word for the Spanish 'talio'. While not directly related, the Greek root 'thallos' meaning 'green shoot' is found in some English botanical terms like 'thallophyte' (simple plants without distinct stems or leaves) and 'thallus' (a plant body without true roots, stems, or leaves).