Iodine-131 (usually in the chemical form of iodide) is a component of nuclear fallout, and is particularly dangerous owing to the thyroid gland's propensity to concentrate ingested iodine, where it is kept for periods longer than this isotope's radiological half-life of eight days.
Magma is composed of molten rock and is stored in the Earthâs crust. Lava is magma that reaches the surface of our planet through a volcano vent. Lava flow, Hawai. Courtesy of the U.S. Geological Society.agma is composed of molten rock and is stored in the Earthâs crust. Lava is magma that reaches the surface of our planet through a volcano vent. Lava flow, Hawai. Courtesy of the U.S. Geological Society.
The molten rock that comes out of a volcano is called lava. When molten it is a liquid. When it hardens it is still lava, now in the solid form. Magma is the term used for lava when it is below the surface. Lava definitions: 1. Molten rock that reaches the earth's surface through a volcano or fissure.