Multiple choice softskills leadership quietude tranquillity spacious agent which brings about a chemical change while it remains unaffected and unchanged thought Reveal answer Fill a bubble to check yourself A Correct answer Explanation Quietude is a state of stillness, calmness, or tranquillity. Spacious (489204) refers to size, a catalyst (489205) affects chemical changes, and thought (489206) is a mental process. Tranquillity is the only synonym for quietness.