键
jiàn · HSK 5
key
🔑 金 (metal) + 建 (build/establish) — the metal piece that establishes a connection
Radical 金 marks it as metal; phonetic 建 (jiàn) gives the sound and hints at 'setting up' or 'establishing.' A 键 is the metal part that locks something in — a key, a keyboard key, or a chemical bond.
键 — metal radical 钅 + 建 jiàn (phonetic)
A semantic-phonetic compound. The metal radical 钅 signals the meaning category — originally a metal pin or bolt used to fasten a cart's wheel to its axle. The right side 建 supplies the sound 'jiàn'. The meaning later extended to 'key' and, in modern usage, the keys of a keyboard or piano.