A geologic sample is found that contains 1,800 uranium-235 atoms and 5,400 lead-207 atoms. How old is this sample?

Ageologist determines that a sample of a mineral can't be scratched by a steel nail but can be scratched by a masonry drill bit. based on this information, the sample mineral has to be softer than a. orthoclase. b. fluorite. c. apatite. d. corundum.

When the speed of the bottle is 2 m/s, the average maximum height of the beanbag is m.

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