Why do x-ray technicians stand behind a shield when giving x-rays to patients? a) because large doses of x-rays cause blindness b) because they can more accurately see the patient's bones c) because they need to protect themselves from patient disease d) because large doses of x-rays are known to cause cell damage and cancers

X-ray technicians stand behind a shield when giving X-rays to patients because large doses of X-rays are known to cause cell damage and cancers.

D

Explanation:

Electromagnetic radiations like x-rays, alpha rays and other cosmic rays are harmful to human health and tissues to some extent when it is exposed for long time.

The x-rays are created when highly accelerated electrons hit the metal leading to ejection of electrons from its shell.

The x-rays are highly penetrate able but it cannot penetrate bones. So it is mostly used for getting scans of bones.

X-rays can penetrate cells and when exposed for large time in large doses it can harm the cell by damaging them or by creating cancer cells.

concave lenses are used here. they spread the light out before it reaches the convex lens in the eye, therefore letting the image focus directly on the retina. hyperopia is known to you probably as farsightedness.