A hydrogen atom lost its electron and went to the police station to file a missing electron report. He was questioned by the police: "Haven't you just misplaced it somewhere? Are you sure that your electron is really lost?"



"I'm positive." replied the atom.

positive 既有 肯定,确定 的意思，也有 正的，阳性 的意思。当原子失去电子后，就变成 正 的了。