We're do Bermuda Triangletake people?

Geologists know that potassium-40 decays to argon-40, with a half-life of 1.3 billion years. if an analysis of a feldspar crystal in a sample of granite shows that 75 percent of the potassium-40 atoms have decayed to form argon-40, what is the age of the granite

Which of the following terms describes the layers of air surrounding the earth ?

Name the two rivers that run through the fertile crescent. how were the rivers both positive and negative to societies of the fertile crescent?