Earth elements decay and change into another element in a process called_____________.

The __________of rocks is the numerical age and real age of rocks.

Geologist use _________ to determine the absolute age of rocks.

All organisms contain the element_________, so it is used to find the ages of fossils.

Geologist use the time it takes for a radioactive isotope to decay to half its original mass called a___________.

Radioactive dating shows ___________ rocks are 4.6 billion years old.

The moon was made from a piece of _________ .

Life on Earth has existed for more than _____________ years.

A long-lived natually occurring radioactive carbon isotope:

The thermal energy transferred by electromagnetic waves is called ____________________