noun[ C ]chemistryspecializeduk/əˌtɒm.ɪk ˈnʌm.bər/us/əˌtɑː.mɪk ˈnʌm.bɚ/
原子数(某种化学物质的原子核中质子的数量,用于化学元素周期表中的排序)
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