reagent
🇺🇸
/riˈeɪdʒənt/
🇬🇧
/riˈeɪdʒənt/
A substance used to test or cause a chemical reaction, often to identify another substance.
The chemist added a few drops of reagent to the mixture to see if it would change color.
化學家向混合物中滴入幾滴試劑,以觀察其是否會改變顏色。