If you get some of these in the upper atmosphere, a photon, an ultraviolet photon, has the energy capable of breaking this bond.

如果你把它放到大气层上，一个光子，一个紫外光光子，有能量可以破坏它的化学键。

麻省理工公开课 - 固态化学导论课程节选

So in order to rotate a double bond, you have to actually break the pi bond, so essentially what you're doing is breaking the double bond.

为了能够旋转双键，你必须打破一个π键，本质上我们要做的就是打破双键。

麻省理工公开课 - 化学原理课程节选

So, if we talk about dissociating h 2, we're going from the h 2 molecule, and breaking this bond right in half, so we now have two individual hydrogen atoms here.

那么，如果我们讨论的是离解氢分子，我们将从氢分子开始，使这个键断裂，一分为二，那么就得到了两个分开的氢原子。

麻省理工公开课 - 化学原理课程节选