柯林斯词典atomic number 1. N the number of protons in the nucleus of an atom of an element 原子序數 ( abbr: at. no. symbol: Also called proton number) 返回 atomic number剑桥词典the number of protons found in the nucleus of an atom of a particular chemical , used as a way of listing the chemical elements in order in the periodic table 原子數（某種化學物質的原子核中質子的數量，用於化學元素周期表中的排序） 返回 atomic number