Name two electromagnetic waves of wavelength smaller than that of violet light. State one use of each.
UV rays and X-rays
Hospitals use UV lamps to sterilise surgical equipment and the air in operating theatres. Food and drug companies also use UV lamps to sterilise their products. Suitable doses of ultraviolet rays cause the body to produce vitamin D, and this is used by doctors to treat vitamin D deficiency and some skin disorders.
X-rays are one type of electromagnetic radiation. They are commonly used in hospitals to produce photographs of bones which can be checked for breaks or fractures. X-rays have the following properties: they can penetrate less dense matter such as skin and body tissue (but not bone)