DONOW (5 MINUTES) If 20.0 gram sample of element Xenaium remains after 72 days determine the
mass of the original sample. The half life of Xenaium-234 is 12 days.

Nebulae are enormous clouds in outer space. they are made mostly of hydrogen gas, helium gas, and dust. some nebulae glow brightly, while others do not. the stars that people see are huge, bright balls of glowing gas. they are made mostly of hydrogen and helium. which statement correctly describes other ways in which nebulae and stars are different? a. stars can form inside a nebula but a nebula can never be produced by any star. b. a star always has a higher density than a nebula. c. stars can never form inside a nebula but a nebula can be produced by any star. d. a nebula always has a higher density than a star.

How does climate change cause the ocean's thermohaline current to slow down?

Many pharmaceutical drugs are organic compounds that were originally synthesized in the laboratory. which two scientific disciplines are bridged by pharmaceutical drugs? chemistry and forensics chemistry and medicine biology and forensics biology and criminology