10kg of a particular type of rock usually has 1000g of Potassium-40. If a 10kg sample of this rock is found and it has 500g of Potassium-40 in it, what is the age of this 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 .

Jason adds the antibiotic penicillin to a bacterial culture. the bacteria develop genetic modifications in their genome, which gives them resistance to the antibiotic penicillin. what caused this genetic modification?

In the practice of science, this type of reasoning is used to develop explanations.