noun 下载 🔗分享 砹 A highly radioactive chemical element (symbol At), one of the halogens, with atomic number 85. Examples : "Due to its extreme radioactivity and rarity, astatine is mostly studied in specialized laboratories and has no common uses in everyday life. " 由于砹具有极强的放射性和稀有性,因此砹主要在专业实验室中进行研究,在日常生活中没有常见用途。 element chemistry science 与AI对话词汇游戏阅读练习