Suppose you found a material in which 12.5% of the orginal radioactive atomes were present. if the half is 470 years, how old is the material

How does the principle of electromagnetism explain the interaction between earth’s magnetic field and the solar wind?

What is a main difference between a mixture and a pure substance? a mixture is only a liquid, but a pure substance can be in any state.a mixture looks the same throughout, but a pure substance does not.1 a mixture can vary in composition, but a pure substance has a set composlo a mixture can be made up of a single compound, but a pure substance car

What are fossils of organisms that existed over a wide area but only for a limited time period called?