You start with O double minus, so that is oxygen plus two electrons.

你从氧二负离子，也就是氯元素带2个负电子。

麻省理工公开课 - 固态化学导论课程节选

times 7, plus we have 6 in the sulfur, and oxygen is right above sulfur, so that also has 6.

二乘上七，加上硫的六个，而氧在硫的正上方，因此也有六个。

麻省理工公开课 - 化学原理课程节选

Because aluminum ions have charge of plus three and oxygen ions have charge of minus two.

因为铝离子为正三价,氧为负二价。

麻省理工公开课 - 固态化学导论课程节选

+6=12 Oxygen has six valence electrons. Six plus six is 12.

氧有6个价电子。

麻省理工公开课 - 固态化学导论课程节选

Aluminum oxide, aluminum plus oxygen.

氧化铝，铝加上氧。

麻省理工公开课 - 固态化学导论课程节选

We put the magnesium 2 plus here, and then we put the oxygen here, O 2 minus, and we know that this gives us our R zero, right?

我们把Mg2+放这，然后O2-放这，我们都知道这给我们的是R0，对么？

麻省理工公开课 - 固态化学导论课程节选