Robert Samnaxtino., age l0 of somerville, Mass., for his question:

How were X rays named?

In math the letter X often stands for the unknown item in a problem. scientists often use an X to name an item of mystery. sometimes they use an X when they do not wish to give the exact amount of a number. X rays were named by Wilhelm Konrad Roentgen soon after he discovered them way back in l895. At that time nobody not even the discoverer knew what they were. so Roentgen, a scientist, called them X rays.

The mysterious rays are invisible, but they are related to visible light. They also are related to radio waves and to the invisible rays of infrared and ultraviolet light. X rays and all these things are forms of electromagnetic energy. But though we now know what they are we still. call them X rays.