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Absolute Dating.pptx
- 1.
- 2. Think About It… •How old is Earth? • What are some tools or methods that scientists could use to figure out the age of the Earth?
- 3. Remember: Geologists use relative datingto figure out if a rock is older or younger than other rock. The older rocks are on bottom and the younger rocks are on top.
- 4. But What IfYou Want to Know the Exact Age? Geologists often also need to know the exact age of a rock or fossil. Finding the exact age of an object is called absolute dating.
- 5. Absolute dating isthe method of measuring the absolute age of an event or object. 01
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- 7. 02 Everything is madeof atoms. The original atom is called the “parent isotope." The new form is called the "daughter isotope."
- 8. Half-life is thetime needed for half of a sample of a radioactive substance to undergo radioactive decay. After every half-life, the amount of parent material decreases by one-half.
- 9. 03 4, 600,000, 000 years old
- 10. T H AN K Y O U
Editor's Notes
- #3 So, in this afternoon we will going to explore and learn more about how old is earth and what are some tools or methods that scientists could use to figure out the age of the Earth? Let’s start!
- #4 As what you have seen in our example the formations of rock, the older rocks are at the bottom and the younger rocks is on the top. This method of identifying the rocks is what we called relative dating.
- #5 Remember: “ABSOLUTE” means exact or definite. Question: What is Absolute Dating?
- #7 As what you can see in the example picture, you can see the exact age of the volcanic ash which is ___________________. Again the top is the younger ones and at the bottom is the older.
- #8 Overtime, some of these atoms may change into a different type of atom. This breakdown of the unstable isotopes or other elements is called radioactive.
- #9 Example A scientist knows that half of the parent atoms will turn into daughter isotopes every 10, 000 years. Originally, there is 16mg of parent isotopes. 10, 000 years go by, half of the 16mg of parents turn into daughter isotopes (16 divided by 2 = 8) So, there are 8mg of daughter isotopes now and there are 8mg of parent isotopes left. 16 – 8- 4- 2
- #10 Scientists have used absolute dating to figure out the age of the Earth. By counting the parent and daughter isotopes in some very old rocks, scientists say that the solar system including Earth is about 4.6 billion years old.