Final answer:
X-rays were discovered in 1895 by German physicist Wilhelm Röntgen. He found that X-rays could pass through flesh and create an image of bones on a screen. This led to the use of X-rays for medical imaging.
Step-by-step explanation:
X-rays were discovered in 1895 by German physicist Wilhelm Röntgen. While experimenting with electrical current, he found that a mysterious and invisible 'ray' would pass through his flesh but leave an outline of his bones on a screen coated with a metal compound. Röntgen made the first durable record of the internal parts of a living human: an 'X-ray' image of his wife's hand. This discovery led to the widespread use of X-rays in detecting injuries and diseases.