Radioactive lava is molten rock that contains radioactive elements, such as uranium or thorium. When a volcano erupts, it can release this lava, which may emit radiation due to the decay of these elements. The level of radioactivity can vary depending on the concentration of these materials in the lava. The presence of radioactive lava is often associated with certain types of volcanic activity, particularly in regions with rich mineral deposits. Areas like the Hawaiian Islands or Iceland may have volcanic rocks that are studied for their radioactive properties, helping scientists understand the geological processes at work.