An asteroid floating through space was recently landed on by a NASA drone. The drone took a sample of the rock layers and found 1/32 of the original Rubidium-87 in the rock layer. The half-life of Rubidium-87 is 48.8 Billion year. How old is the rock?

What is driving behind plate tectonics (plate movment)? a) gravity only b) inertia c) convection and gravity d) the sun theres no option for science so i picked chemistry. plz

What does the process of natural selection involve

Select the correct text in the passage. which sentences describe examples of sustainable living? i live in an old apartment building downtown, but my company is based in an office park on the outskirts of the city. i drive an old car that needs to be replaced. i plan to buy a hybrid for better gas mileage, but for now i am able to carpool with a couple of friends from work. the drive to the office park is about 45 minutes each way, but we do get to work in a modern building. the architects just received a leed certification for the design.