Learning Objective: I will be able to explain how we use half lives to determine the age of a rock.

Success Criteria: I can use the ESRT to determine the half live of common radioisotopes. I can correctly follow procedures to complete my lab. I can graph the data collected.

When an unstable radioactive element changes into a stable element Radioactive Decay When an unstable radioactive element changes into a stable element

Example Unstable Radioactive Isotope Stable Decay Product Carbon 14 (C14) Nitrogen 14 (N14) Uranium 238 (U238) Lead 206 (Pb206) Parent Daughter

Radiometric Dating Half life: The time required for 1/2 of a parent material to break down to daughter material

Radiometric Dating The half lives of radioisotopes vary depending upon the isotope Examples: C14 = 5,770 years U238 = 4,500,000,000 years Rb87 = 47,000,000,000 years

Carbon 14 is used to date biological remains Carbon is incorporated into the cells of living organisms and begins to decay when the organism dies Uranium 238 is used to date rocks Larger half life

If half the K -40 of a rock has decayed into Ar-40, how old is the rock? How many years would it take for 75 % of a sample of K-40 to disintegrate?

Half Life M&M Lab Learning Objective: I will be able to explain how we use half lives to determine the age of a rock. Success Criteria: I can use the ESRT to determine the half live of common radioisotopes. I can correctly follow procedures to complete my lab. I can graph the data collected.

A sample that has ½ c-14 and ½ n-14? How old are: A sample that has ½ c-14 and ½ n-14? A sample that has ¼ K-40 and ¾ Ar-40? A sample that has ½ U-238 ½ Pb-206?

How old are: A sample that has 1/8 Rb-87 and 7/8 Sr-87? A sample that has ¼ C-14 and ¾ N-14? A sample that has ¾ C-14 and ¼ N-14?

What fraction remains of: May 19 A 50 billion year old sample has ____ Rb-87 and ____ Sr-87. A 2.6 billion year old sample has____ K-40 and ____Ar-40. Allen

Stranz should take a break ;) This is so boring Stranz should take a break ;)