The negative ions, these are electron-rich.

二负离子，它们有富裕的电子。

麻省理工公开课 - 固态化学导论课程节选

But, can you see that as you get really close together the negative electronic cloud surrounding the two ions start to sense one another.

然后当你真的让它们,离得很近时,这两个离子周围的负电子云能感应到对方。

麻省理工公开课 - 固态化学导论课程节选