We could also figure out the formal charges, and obviously the formal charges between these two atoms, they're going to be identical, we're only dealing with oxygen atoms here.

我们还可以把形式电荷算出来，显然这两个原子的形式电荷，应该是完全相同的，我们要处理的只有氧这一种原子。

麻省理工公开课 - 化学原理课程节选