**Question:** True about X-rays:

A. X-rays are used to diagnose bone fractures
B. X-rays can penetrate soft tissues but not bones
C. X-rays cause cancer in humans
D. X-rays are absorbed by dense materials like lead

**Core Concept:** X-rays are electromagnetic radiation that can pass through certain materials and are absorbed by others. In medicine, they are used for imaging purposes, particularly to diagnose bone fractures. X-rays penetrate bones but not soft tissues, which is useful for detecting fractures and other bone abnormalities. However, excessive exposure to X-rays can cause cancer due to the ionizing nature of the radiation. X-rays are absorbed by dense materials like lead, which is why lead aprons are used during X-ray procedures to protect patients and medical personnel from unnecessary radiation exposure.

**Why the Correct Answer is Right:**

Option A is correct because X-rays are used to visualize bone fractures due to their ability to penetrate bones and reveal internal structures. This is useful in diagnosing bone injuries and other bone-related conditions.

Option B is correct because X-rays are absorbed by dense materials like lead, which enables them to be shielded and protects patients and medical personnel during procedures. Soft tissues, on the other hand, are not transparent to X-rays and thus can obscure the images obtained.

Option C is incorrect because X-rays, though ionizing, do not cause cancer in all cases. The risk depends on the dose of radiation received, with higher doses increasing the likelihood of cancer induction.

Option D is incorrect because X-rays penetrate bones, not soft tissues. Their primary advantage lies in their ability to visualize bones, making this option incorrect.

**Why Each Wrong Option is Incorrect:**

Option C (causes cancer) is incorrect because the risk of cancer induction depends on the dose of radiation received. While X-rays are ionizing radiation, the risk is not universal and depends on the cumulative dose one is exposed to.

Option D (penetrates soft tissues) is incorrect because X-rays predominantly interact with dense materials, such as bones, not soft tissues. Their primary advantage is their ability to visualize bones, not soft tissues.

**Clinical Pearls:**

1. **X-rays are a valuable diagnostic tool for imaging bones and detecting fractures, infections, and tumors.**
2. **Use of lead aprons and shielding during X-ray procedures helps minimize radiation exposure.**
3. **Understand the probability of cancer induction by ionizing radiation to appreciate the risk-benefit ratio in clinical practice.**
4. **X-rays primarily interact with dense materials, such as bones, rather than soft tissues.**