Harmful bacteria can be seen in the UV-C spectrum with black light. UV-C light has a wavelength range of 100-280 nanometers and is able to penetrate the cell walls of bacteria, disrupting their DNA and killing them. This makes UV-C light an effective tool for disinfection and sterilization in various applications, such as water treatment, air purification, and surface decontamination. **

UV-C lamps shine blue because they emit light in the ultraviolet spectrum, which is not visible to the human eye. However, some UV-C lamps are coated with a phosphor material that absorbs the UV-C light and re-emits it as visible blue light. This process is called fluorescence, and it causes the UV-C lamp to appear blue when it is turned on. The blue light emitted by the lamp serves as a visual indicator that the UV-C lamp is operating and emitting ultraviolet light. **

Scorpions glow under UV light due to a substance in their exoskeleton called hyaline, which contains fluorescent chemicals that react to the UV light. This causes the scorpions to emit a blue-green glow, which is thought to help them detect and avoid UV light, as well as potentially attracting prey. The exact purpose of this fluorescence is still not fully understood, but it is believed to play a role in their survival and behavior in their natural habitat. **

Yes, there are plants that glow under UV light. Some plants, like certain types of flowers and algae, have the ability to produce fluorescent or phosphorescent compounds that emit light when exposed to ultraviolet light. This phenomenon is known as biofluorescence and is thought to help attract pollinators or serve as a form of protection against harmful UV radiation. One well-known example of a plant that glows under UV light is the Arabidopsis thaliana, a small flowering plant commonly used in scientific research. **

The paper that does not glow under UV light is the paper that contains no fluorescent agents or chemicals. Fluorescent agents are added to some papers to make them glow under UV light, while papers without these agents will not exhibit any fluorescence. This can be useful in distinguishing between different types of paper or verifying the authenticity of documents. **

The UV tube glows weakly violet because it emits ultraviolet light, which is not visible to the human eye. However, a small amount of visible light is also emitted as a byproduct of the UV light production process. This visible light appears as a weak violet glow due to the specific wavelengths of light being emitted by the tube. The weak violet glow is a result of the combination of the UV light and the small amount of visible light being emitted. **

An emission spectrum is produced when an atom or molecule emits light at specific wavelengths, resulting in bright lines on a dark background. This occurs when electrons in the atom or molecule move from higher energy levels to lower energy levels, releasing energy in the form of light. On the other hand, an absorption spectrum is produced when an atom or molecule absorbs light at specific wavelengths, resulting in dark lines on a continuous spectrum. This occurs when electrons in the atom or molecule move from lower energy levels to higher energy levels, absorbing energy from incoming light. **

Yes, plasma has both an absorption spectrum and an emission spectrum. When light passes through a plasma, certain wavelengths are absorbed by the atoms or ions in the plasma, creating an absorption spectrum. Conversely, when the atoms or ions in the plasma are excited and then return to their ground state, they emit light at specific wavelengths, creating an emission spectrum. These spectra can be used to identify the elements present in the plasma and to study their properties. **