柯林斯詞典alkali metal 1. N any of the monovalent metals lithium, sodium, potassium, rubidium, caesium, and francium, belonging to group 1A of the periodic table. They are all very reactive and electropositive 堿金屬 返回 alkali metal劍橋詞典any of a group of soft , white metals that are chemical elements and react easily with other substances 堿金屬 返回 alkali metal