A college chemistry professor could not help but notice that
one of his students was late to class for the third time that
week.

Before class ended he went around the room asking
students some questions about the day's lecture.

Of course,
he made sure to pick on his tardy pupil.

"And who was it that discovered uranium?" the professor asked.

"I don't know," the student said.

"Perhaps if you came to class on time, Mr. Winters, you would
know," said the professor.

"That's not true," the student replied. "I never pay attention!"