Earth Science - Absolute Dating

How does absolute age differ from relative age?

• only absolute dating indicates which rock is older than another
• only absolute dating finds the age in years
• only relative dating finds the age in years

Which of the following isotopes would be best to find the age of the Earth?

• Rb-87

  half-life = 49 billion years

• C-14

  half-life = 5730 years

• Al-26

  half-life = 740,000 years

• K-40

  half-life = 1.3 billion years

The length of time required for half of the radioactive atoms in a sample to decay is its...

• era
• age
• half-life
• eon

Tags

NGSS.HS-PS1-8

What is the half-life of iodine-131?

• 32 days
• 8 days
• 16 days
• 24 days

Tags

NGSS.HS-PS1-8

What is the Half life of this isotope?

• 5 seconds

• 10 seconds

• 15 seconds

• 20 seconds

Tags

NGSS.HS-PS1-8

If the half-life of a radioactive group of atoms is 300 years, then how old is the rock if there have been three half-lives?

• 37.5 years

• 100 years

• 600 years

• 900 years

Tags

NGSS.HS-PS1-8

If you had 1000 atoms of parent isotope, then how many parent atoms would you have after 1 half-life?

• 75 atoms

• 250 atoms

• 500 atoms

• 125 atoms

Tags

NGSS.HS-PS1-8

How many half-lives have passed if there 12.5% parent isotope left?

• 1 half-life

• 2 half-lives

• 3 half-lives

• 4 half-lives

If the half-life of a radioactive group of atoms is 100 years, then how old is the rock if there 12.5% parent isotope left?

• 50 years

• 100 years

• 200 years

• 300 years

Tags

NGSS.HS-PS1-8

If you had 1000 atoms of parent isotope, then how many parent atoms would you have after 3 half-lives?

• 75 atoms

• 250 atoms

• 500 atoms

• 125 atoms

Tags

NGSS.HS-PS1-8