Answer: Crust, mantle and core 4. Question: How many elements are on the periodic table? Answer: 118 5. Question: What do you call an animal that eats a variety of other organisms, including plants, ...

As India and Pakistan engage in their most intense military conflict in decades, the nuclear question looms large. With both ...

For the first time, astronomers have probed the physical environment of repeating X-ray outbursts near monster black holes ...

For years, astronomers have toyed with the idea that the Sun hides an extra planet so distant and dim that even the best ...