Final answer:
UV lamps with a nickel glass filter are polychromatic, emitting primarily UV light, which contains multiple wavelengths. Viewed without specialized equipment, they might seem to emit monochromatic light as visible light is blocked and humans cannot see UV light.
Step-by-step explanation:
The UV lamp with a nickel glass filter that blocks visible light would emit light that is primarily ultraviolet (UV), making it polychromatic because UV light itself contains a range of wavelengths. However, the term monochromatic refers to light of a single wavelength and polychromatic refers to light that contains multiple wavelengths. UV light contains multiple wavelengths, but since visible light is blocked, we cannot observe the spectrum without specialized equipment.
In practical terms, though, such a lamp might seem to emit monochromatic light to the human eye, as we cannot see UV light and no visible light is present. Transparent materials generally do not absorb visible light due to lacking the energy steps required for absorption. At the same time, UV light has higher photon energy compared to visible light, capable of ionizing material and thus is often absorbed by the material. The absorption and subsequent emission processes, such as those in fluorescent light tubes, demonstrate the complex interactions between light and materials.