Lab Report Atomic Dating

Lab Report
Atomic Dating Using Isotopes

Answer the following questions about the results of this activity. Record your answers in the boxes.

Send your completed lab report to your instructor. Don’t forget to save your lab report to your computer!

Reference: Isotope Half-Life Chart
Isotope
Product
Half Life
Carbon-14
Nitrogen-14
5730 years
Potassium - 40
Argon - 40
1,280 million years
Rubidium - 87
Strontium -8 7
48,800 million years
Thorium - 232
Lead – 208
14,010 million years
Uranium - 235 Lead - 297
704 million years
Uranium - 238 Lead - 206
4,470 million years

Activity 1 – Calibration
Place your data from Activity 1 in the appropriate boxes below. Calculate the age of the calibration standards using the following information.

Fraction of sample remaining = remaining ppm of sample/initial ppm of sample
Age of sample = half-life value of isotope X number of half-lives elapsed

Calibration Standard

Initial ppm

Remaining ppm

Age of Standard

Low
Carbon-14

12000

5998

6000

High
Uranium-235

600000

151000

150000

1. Explain if the instrument appears to be calibrated based on the data you obtained for the Low Calibration Standard.

2. Explain if the instrument appears to be calibrated based on the data you obtained for the High Calibration Standard.

3. Explain which would be the best isotope from the Isotope Half-Life Chart to measure a 3 billion year old specimen.

Debra Holt

Carbon dating is very useful in learning to understand the changes in our

world, and the changes that life has gone through. I have learned that using different

isotopes are not always the best because some isotopes have very