劍橋詞典the mass of an atom of a particular chemical element , usually expressed in atomic mass units 相對(duì)原子質(zhì)量,原子量(某種特定化學(xué)元素一個(gè)原子的質(zhì)量,通常以原子質(zhì)量單位表示) 比較atomic mass 返回 relative atomic mass