1. At the bell
Filling out your planner and sitting quietly
Split a blank piece of paper with a partner
Or come grab scrap paper off my desk

2. Vocabulary Review
Unconformity-
Law of Superposition-
Absolute age dating-

3. Absolute Age Dating

4. Absolute Age Dating
the process of establishing the age of an
object by determining the number of years it
has existed
Scientists have figured out an exact or
precise age
We are absolutely sure of the age

5. Chemistry Review
●
What parts make up an atom?

6. What does it mean to be
radioactive?
Radioactivity- the spontaneous decay of certain
unstable atomic nuclei
But what does that mean?

7. Radioactive Isotope
●
●
Means we have an element with a
changed mass
It has more neutrons!

8. Radiocarbon dating
When an organism dies, the amount of carbon-14
it contains gradually decreases as it decays.
By comparing the ratio of carbon-14 to carbon-12
in a sample, radiocarbon dates can be
determined.

9. All elements have radioactive
isotopes
Some just don't have any stable forms like
●
Uranium
●
Radon
●
Radium
●
Plutonium

10. Parent Material
●
Is the radioactive isotope you start with
Like Uranium

11. Half Life
A half-life is the amount of time necessary for
one-half of the nuclei in a sample (parent) to
decay to a stable isotope (daughter).

12. Daughter Material
●
Is whatever element the radioactive
isotope decays to

13. After one half-life
Only half the parent material remains
So after 2 half lives…..how much remains?

14. Which is less stable
The parent isotope or the daughter product?

15. Cobalt-60
The half-life of cobalt-60 is 5 years.
If you have 10 grams of Co-60,
how much do you have after 15 years?