Hypernyms (tenant is a kind of...): bearer; holder (the person who is in possession of a check or note or bond or document of title that is endorsed to him or to whoever holds it) Hyponyms (each of the following is a kind of tenant): cotenant (one of two or more tenants holding title to the same property)
Exposure from terrestrial radiation. The composition of the earth's crust is a major source of natural radiation. The main contributors are natural deposits of uranium, potassium and thorium which, in the process of natural decay, will release small amounts of ionizing radiation.-rays: X-rays are a form of radiation similar to gamma radiation but they are produced mainly by artificial means rather than from radioactive substances. Neutron radiation: Neutron radiation occurs when neutrons are ejected from the nucleus by nuclear fission and other processes.
Sun is the primary source of natural light, and lightbulbs or lamps are the artificial sources. Light is a form of electromagnetic energy that, in the case of natural light, comes from the sun as the source and, in case of artificial light, illuminates via energy from another source. No matter what the source, light has an impact on life on earth as a whole. Sun is the most powerful source of light.