The preserved remains or evidence of ancient living things is a. index fossil b. fossil c. unconformity superposition

volcanoes (an event in the geosphere) release a large amount of particulate matter into the atmosphere. these particles serve as nuclei for the formation of water droplets (hydrosphere). rainfall (hydrosphere) often increases following an eruption, stimulating plant growth (biosphere).

sodium i think the chemical element of atomic number 11, a soft silver-white reactive metal of the alkali metal group.