So what actually turns out the reality is that h e 2 does exist, but it exists as the weakest chemical bond known, and it wasn't, in fact, even found to exist until 1993, so I can assure you this is not a bond that you see very often in nature, and it is a very, very weak bond.

实际上He2键是存在的，但它是目前所知的最弱的键，直到1993年它才被发现，所以我可以向你们保证在,自然界你们不可能经常看到它，它是种非常非常弱得键。

麻省理工公开课 - 化学原理课程节选

So what we see is a bond order of 0, and again, the bond is very, very weak.

我们看到键序是0，同样的，键非常非常的弱。

麻省理工公开课 - 化学原理课程节选