10 letters · 18 points in Scrabble
noun responsive to stimulation
noun ready susceptibility to chemical change
originEtymology tree English react Proto-Indo-European *-wós Proto-Indo-European *-iHwósder. Latin -īvus Old French -ifbor. Middle English -yf English -ive English reactive Proto-Indo-European *-teh₂ Proto-Indo-European *-ts Proto-Indo-European *-teh₂ts Latin -itāsder. Old French -itebor. Middle English -ite English -ity English reactivity From reactive + -ity.
Etymology from Wiktionary, CC BY-SA 3.0