Final answer:
A hospital scanner is the device that emits ionizing radiation, which is used in the medical field for imaging and treatment. It is capable of causing ionization in atoms and poses health risks, thus its exposure is usually kept to a minimum.
Step-by-step explanation:
The device among the given options that emits ionizing radiation is a hospital scanner. Specifically, hospital scanners such as CT scanners and X-ray machines emit ionizing radiation, which is a form of radiation with enough energy to remove tightly bound electrons from atoms, creating ions. Ionizing radiation is used in the medical field for imaging and treatment, as it can penetrate body tissues and provide images of bones and organs. However, it is important to minimize exposure to ionizing radiation due to its potential health risks, which can include damage to living tissue and increased risk of cancer.Ionizing radiation is utilized in medical imaging devices, such as CT scanners, X-ray machines, and other hospital scanners. Geiger counters, scintillators, and dosimeters are tools that can measure this type of radiation. Notably, the other options listed (computer monitor, fluorescent light, tanning bed) typically emit non-ionizing radiation, which is less energetic and less likely to cause damage to DNA or cells.