What are the 4 elements of environmental determinism

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

What is the main source of phosphorus?

According to the article about the zhou dynasty, this dynasty was broken into different eras because its capital changed from place to place. how many different eras were there in the zhou dynasty? a. two b. six c. ten d. fourteen