What is saudi arabia's major export?

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

The magnitude of an earthquake is typically calculated according to the scale.           a. mercalli   b. fujita   c. richter   d. saffir-simpson  

Explain how earths tilt and revolution around the sun affects weather and climate