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
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
Scientists have figured out an exact or
We are absolutely sure of the age
5. Chemistry Review
What parts make up an atom?
6. What does it mean to be
Radioactivity- the spontaneous decay of certain
unstable atomic nuclei
But what does that mean?
7. Radioactive Isotope
Means we have an element with a
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
9. All elements have radioactive
Some just don't have any stable forms like
10. Parent Material
Is the radioactive isotope you start with
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?
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?