This will be the definition of the mole as the amount of carbon weighing exactly 12 grams, so I would like to know now how many particles, how many carbons are there in that mole.

摩尔的定义就是,12克的碳的数量，我想知道有多少粒子，一摩尔会有多少碳粒子。

麻省理工公开课 - 固态化学导论课程节选

We have carbon 12. I will even leave off the 6 because we already know it is carbon.

我们有碳12，我们将6省去6,因为我们已经知道它是碳了。

麻省理工公开课 - 固态化学导论课程节选

So carbon 12. We know that it has the proton number, by definition, is 6. And the neutron number, 6 from 12 is 6. So it has 6 protons and 6 neutrons.

所以碳12，我们知道它有质子数，根据定义，那就是6，而电子数，12减6等于6，所以它有6个中子。

麻省理工公开课 - 固态化学导论课程节选