Date rocks and fossils with radioactive decay
11th grade (Year 12 in England) · 16 questions · Common Core: NGSS.HS-ESS1-5, NGSS.HS-ESS1-6, NGSS.SEP 5 · England: GCSE Physics: Atomic structure (half-life uses), A level Geology/Physics links
Name
Date
Score/ 16
Question 1
In a volcanic rock, potassium-40 decays to argon-40 with a half-life of 1.25 billion years. The rock now contains 7 atoms of argon-40 for every 1 atom of potassium-40 (assume all the argon came from decay). How old is the rock, in billions of years?
Answer
Question 2
Which isotope is best for dating the oldest rocks on Earth (billions of years)?
- A. radon-222 (half-life about 4 days)
- B. carbon-14 (half-life 5730 years)
- C. uranium-238 (half-life about 4.5 billion years)
- D. iodine-131 (half-life 8 days)
Question 3
A piece of ancient wood has 25 % of the carbon-14 found in living wood. The half-life of carbon-14 is 5730 years. How old is the wood, in years?
Answer
Question 4
In a volcanic rock, potassium-40 decays to argon-40 with a half-life of 1.25 billion years. The rock now contains 1 atoms of argon-40 for every 1 atom of potassium-40 (assume all the argon came from decay). How old is the rock, in billions of years?
Answer
Question 5
Radiometric dating gives the age of Earth as about 4.5 billion years. Which samples gave this result?
- A. meteorites and the oldest mineral grains, dated with uranium–lead
- B. dinosaur bones dated with carbon-14
- C. tree rings
- D. ice cores
Question 6
A piece of ancient wood has 50 % of the carbon-14 found in living wood. The half-life of carbon-14 is 5730 years. How old is the wood, in years?
Answer
Question 7
In a volcanic rock, potassium-40 decays to argon-40 with a half-life of 1.25 billion years. The rock now contains 7 atoms of argon-40 for every 1 atom of potassium-40 (assume all the argon came from decay). How old is the rock, in billions of years?
Answer
Question 8
Radiometric dating gives the age of Earth as about 4.5 billion years. Which samples gave this result?
- A. dinosaur bones dated with carbon-14
- B. ice cores
- C. meteorites and the oldest mineral grains, dated with uranium–lead
- D. tree rings
Question 9
A piece of ancient wood has 6.25 % of the carbon-14 found in living wood. The half-life of carbon-14 is 5730 years. How old is the wood, in years?
Answer
Question 10
In a volcanic rock, potassium-40 decays to argon-40 with a half-life of 1.25 billion years. The rock now contains 3 atoms of argon-40 for every 1 atom of potassium-40 (assume all the argon came from decay). How old is the rock, in billions of years?
Answer
Question 11
Why can't carbon-14 be used to date dinosaur bones?
- A. Carbon-14 is not radioactive
- B. Its half-life is too short; almost none would be left after millions of years
- C. Bones never contain isotopes
- D. Dinosaurs contained no carbon
Question 12
A piece of ancient wood has 12.5 % of the carbon-14 found in living wood. The half-life of carbon-14 is 5730 years. How old is the wood, in years?
Answer
Question 13
In a volcanic rock, potassium-40 decays to argon-40 with a half-life of 1.25 billion years. The rock now contains 1 atoms of argon-40 for every 1 atom of potassium-40 (assume all the argon came from decay). How old is the rock, in billions of years?
Answer
Question 14
Why can't carbon-14 be used to date dinosaur bones?
- A. Carbon-14 is not radioactive
- B. Its half-life is too short; almost none would be left after millions of years
- C. Dinosaurs contained no carbon
- D. Bones never contain isotopes
Question 15
A piece of ancient wood has 12.5 % of the carbon-14 found in living wood. The half-life of carbon-14 is 5730 years. How old is the wood, in years?
Answer
Question 16
In a volcanic rock, potassium-40 decays to argon-40 with a half-life of 1.25 billion years. The rock now contains 15 atoms of argon-40 for every 1 atom of potassium-40 (assume all the argon came from decay). How old is the rock, in billions of years?
Answer
All done? Color in the animal! · Free from eurekami.com/math