noun 下载 🔗分享 铯 The chemical element (symbol Cs) with an atomic number of 55. It is a soft, gold-colored, highly reactive alkali metal. Examples : "Example Sentence: "Because cesium is so reactive, scientists store it in oil to prevent it from reacting with the air." " 由于铯的反应性极强,科学家们将它储存在油里,以防止它与空气发生反应。 element substance chemistry material science 与AI对话词汇游戏阅读练习