That is metallic sodium that would keep in kerosene so it doesn't react with the oxygen in the air.

金属钠应该保存在没有中,这样它就不会和空气中的氧气反应了。

麻省理工公开课 - 固态化学导论课程节选

And I know that sodium chloride forms because, if I look on the webpage at 3.091, you see this down here, this is sodium in kerosene.

我知道氯化钠形式，因为我看过3。091的网站，看看这个，这是钠在煤油中。

麻省理工公开课 - 固态化学导论课程节选