You have a sample that contains 35 grams of Uranium-235 and 525 grams of Lead-207. Uranium-235 has a half life of 713 m. y. How old is the sample?

After getting the slide and microscope ready, stella is eager to see the microscopic pond water specimen! she crouches around her microscope and aligns her eye with the microscope’s eyepiece. but she's only able to see a bright white light. at this point, no specimens or cells are visible on stella's pond water slide. after taking a moment to collect her thoughts, stella realizes she can't see any lifeforms because .

Which of these serves as a reference for comparison during a scientific investigation? a)outcome variable (dependent variable) b) test variable (independent variable) c)control group d)hypothesis

In 1992, hurricane andrew left a wake of destruction through florida. one victim of the storm was a reptile-breeding facility. over 900 burmese pythons were set free, and today thousands of pythons live in florida. these pythons are an invasive species, or a harmful species not native to the region. 1. what impacts do you think the burmese pythons might have on local ecosystems