The half-life of halfnium-156 is 0.025 seconds. What was the original amount of the substance if after 0.1 seconds 3.125 gram remains? (A: 25 g)

Which of the following statements is most likely correct about a rock belonging to the jurassic age and a rock belonging to the cambrian age? options: 1) they have identical fossils of organisms that have evolved over time. 2) both have animal fossils preserved in them due to weathering and erosion. 3) they contain different fossils because life on earth has changed through time. 4) the fossils in them were formed on the surface of earth due to exposure to sunlight.

What are the pros and cons of quadrat sampling?

Can a trait be both polygenic and have multiple alleles? explain why or why not.