周期系 zhōuqīxì periodic system Definitions Defs Origin Strokes Stroke Words Sentences Sents 周期系 (週期系) zhōuqīxì periodic system the systematic classification and arrangement of chemical elements according to their atomic numbers and recurring chemical properties Sources Definitions CC-CEDICT
周期系 (週期系) zhōuqīxì periodic system the systematic classification and arrangement of chemical elements according to their atomic numbers and recurring chemical properties Sources Definitions CC-CEDICT
