A crystal contains a radioactive isotope that has a half-life of 20,000 years. You analyze a sample and find that one-eighth of the isotope remains (12.5%). How old is the sample? How many half-lives have passed?

What are 2 major reservations of carbn dioxide on earth

The digestive system absorbs nutrients from food

Which is an example of condominance

A population of cheetahs has a birth rate of 5 and a death rate of 15. Immigration is 2, and emigration is 4. What is its population growth? - 14 - 12 12 14

The structure that covers the gills is the __? A. Lateral line B. Operculum C. Caudal

Where would you find hydrogen bonds in proteins?

Of all the animals in the animal kingdom which one (s) would have the best chance for survival in mountains?

Erica and Jim are given a closed container of ice. They find the mass of the container and ice to be 28.0 grams. The container of ice is left on the lab table overnight. The next day, Erica and Jim observed the container. All of the ice had melted.

Which lists the structures, in correct order, through which light passes when it enters the eye? cones, pupil, lens, sclera, sclera, iris, pupil, lens vitreous humor, lens, pupil, cornea cornea, pupil, lens, vitreous humor

Which of the following does not require a medium through which to travel in word which can travel through empty space