atomic mass number[物] 原子质量数
atomic c number原子序数;原子序
atomic ma number原子质量数
atomic colouring number原子的染色序数
low-atomic-number低原子序数的
low-atomic-number material低原子序数材料
material low-atomic-number低原子序物质
even atomic number偶数原子序数
atomic number contrast原子序数衬度;原子序数反差
N（名词） the number of protons in the nucleus of an atom of an element 原子序数 ( abbr: at. no. symbol: Also called proton number)