Which of the following is NOT a use of gamma rays?

Gamma rays are a form of electromagnetic radiation with very high energy and are used in various applications due to their penetrating power and ability to kill or sterilize living cells. They have important roles in areas such as medical treatments and sterilization processes.

Killing bacteria is a well-documented use of gamma rays, as they can effectively destroy microorganisms, making them useful for sterilization purposes. Similarly, gamma rays are frequently employed in the treatment of certain cancers. Their high energy allows them to target and destroy cancerous cells while sparing surrounding healthy tissue when administered with precision. Additionally, in the context of sterilizing equipment, gamma rays can eliminate pathogens, making them widely used in the medical and laboratory settings.

In contrast, scanning unborn babies typically involves the use of ultrasound, which is a much safer technique compared to gamma rays. While gamma rays can penetrate tissues, reliance on such high-energy radiation for prenatal imaging presents significant risks to the developing fetus. Therefore, the use of gamma rays for scanning unborn babies is not appropriate or common practice, making it the correct identification of a use that does not appropriately align with the established applications of gamma radiation.