Radioactive decay of 40K atoms in an igneous

rock has resulted in a ratio of 25 percent 40K

atoms to 75 percent 40Ar and 40Ca atoms.

How many years old is this rock?

(1) 0.3 10^9 y (3) 2.6 10^9 y

(2) 1.3 10^9 y (4) 3.9 10^9 y

Which of the following is a consequence of using fossil fuels as an energy source.

According to this relief map, which place has the lowest elevation?

An earthquake occurs when magma travels from the magma chamber through the pipe and out through the vent. true or false

Discuss the features of Alexandria that show it was a center of Hellenistic Culture.

Research shows that Mount Everest grows an average of 4 millimeters each year. How many years will it take to grow 720 millimeters

Which region consists of a central place and the surrounding places affected by it?

Which statement about the economy of France is not true? Paris is a major manufacturing center. Marseille is a busy seaport on the Mediterranean coast. Farming is the major activity in the Alps. World-famous wines are produced in the Bordeaux region.

What is agreed upon by scientist as the most likely cause of the final extinction for the dinosaurs?

As a result of a mountainous terrain, all of the following occurred except: A independent Greek city-states arose B large empires developed C trade and outdoor markets developed D outdoor civic life flourished

Why do cities form and how have they affected culture?