short for chemistry : the scientific study of the basic characteristics of substances and the ways in which they react or combine

I failed chem in high school. 我高中化学不及格。

Does he love you for your charm, or because you let him copy your chem notes? 他爱你是因为你的魅力，还是因为你让他抄了你的化学笔记？

short for chemical

Two backup generators failed when the chem plant lost power. 化工厂停电时，两台备用发电机也出了故障。

We believe they were developing bio and chem weapons. 我们相信他们正在开发生化武器。