Final answer:
X-rays are a form of high-energy electromagnetic radiation used in medicine to visualize body structures such as bones.
Step-by-step explanation:
X-rays are a form of high-energy electromagnetic radiation that have a short wavelength and are capable of penetrating solids and ionizing gases. They are used in medicine as a diagnostic tool to visualize body structures such as bones. X-rays can penetrate soft tissues, but they are blocked by denser materials like bones, allowing us to create images of the shadows of bones inside the body.