弹性
tánxìng · HSK 7
elasticity
🪀 弹 (bounce/spring) + 性 (quality/nature) = the quality of bouncing back = elasticity
弹 tán means to spring or bounce (as a released coil); 性 xìng marks an abstract property, like the -ity in elasticity. Together: the bounce-back property of a material.
弹 — bow 弓 + single 单 (phonetic)
Originally a pictograph of a bow with a pellet ready to launch, 弹 depicted a slingshot or pellet bow. The form was later regularized as a phono-semantic compound: 弓 (bow) gives the meaning of shooting or springing, while 单 supplies the sound. Modern senses—bullet, to pluck, to spring—all extend from this shooting/elastic-release idea.
性 — heart radical 忄 + 生 (life/birth)
性 is a semantic-phonetic compound. The heart radical 忄 supplies the meaning, pointing to inner feelings or innate qualities, while 生 ('birth, life') gives the sound and hints at what one is born with. It originally meant 'inborn nature' and later extended to 'character,' 'gender,' and 'sex.'