1990 年
物理 · 共 31 題 · 點擊選項即時核對答案
只看錯題本頁已答 0 / 1
31.
If the nucleus of an atom is represented by the symbol , it means that this atom has
(1) protons in its nucleus.
(2) electrons outside its nucleus.
(3) neutrons in its nucleus.
物理 · 共 31 題 · 點擊選項即時核對答案
If the nucleus of an atom is represented by the symbol , it means that this atom has