Question

what is a substance that gives off high-energy particles or rays

scanner
radioisotope
barium
half-life

Explanation:

Analyze the question prompt

The question asks for the term that describes "a substance that gives off high-energy particles or rays."

Evaluate the given options

• scanner: An imaging device used to detect radiation or capture images, not a substance itself.
• radioisotope: An unstable form of a chemical element that releases radiation (high-energy particles or rays) as it decays to a more stable form.
• barium: A contrast medium used in imaging (like X-rays) to highlight digestive tracts, but it does not emit high-energy radiation on its own.
• half-life: The time required for half of the atoms of a radioactive substance to decay, which is a measurement of time rather than a substance.

Select the correct term

The definition matches "radioisotope."

Answer:

• scanner
• radioisotope (Correct answer)
• barium
• half-life