Now, remember, the formation of the ionic bonds was from group one and group two, and over here with group six and seven.

现在请记住，离子键的形成,从第一族和第二族元素，与六七主族的元素相互构成的。

麻省理工公开课 - 固态化学导论课程节选

So, those are the ones that most likely form ionic bonds.

因此，这些几乎都是离子键。

麻省理工公开课 - 固态化学导论课程节选

So, somewhere in between, the bonds are, we have a range of bonds between ionic on the one hand, and perfectly covalent on the other hand.

因此在中间，这些键，一方面是离子性，另一方面是完美的共价键。

麻省理工公开课 - 固态化学导论课程节选