Give me an example and explain a time in our history when the U. S. has had to deal with the "guns or butter" issue. What did they do?

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 is evidence to the past existence of glaciers?

What is the approximate chemical composition of the solar nebula?