The metal alloy that makes up the core of Earth is , as compared to the rocky mantle. A. less dense B. denser C. very similar in chemistry and density D. distinct in chemistry but of very similar density

In 1933 the 21st amendment was added to the u. s. constitution, allowing for the manfacture, transportation, and sale of alacoholic beverages in the united states. why was this amendment needed?

What is the amount of organic matter in all living organisms in a habitat called?

Some gamma ray bursts are hypothesized to come from mergers of neutron stars or black holes. if this hypothesis is correct, what else should we in principle be able to detect from such mergers? a. gravitiational waves b. x-ray bursts c. significant disruption of gas thousands of light-years away in the surrounding galaxy d. an "afterglow" of bright visible light, lasting for weeks