Absolute Age & Half-Life

Why are isotopes with short half-lives not useful for dating very old rocks?

• because not enough of the parent isotope remains to measure accurately
• because not enough of the daughter product has formed to be detectable
• because neither the parent isotope nor the daughter product will be detectable
• because very old rocks would never have contained these isotopes

Tags

NGSS.HS-PS1-8

Scientists use radioactive decay to measure...

• relative time
• absolute time
• half-lives
• time of day

Tags

NGSS.HS-PS1-8

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

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

Radiometric dating is possible because the rates of decay of radioactive isotopes _____.

• change over time
• change from place to place
• are constant
• vary widely

Tags

NGSS.HS-PS1-8

The time it takes for 50% of the nuclei in a radioactive sample to decay to its stable isotope is called _____.

• the daughter product
• geologic time
• the half-life
• the half-time

Tags

NGSS.HS-PS1-8

If the half-life of a radioactive group of atoms is 100 years, then how old is the rock if there have been two half-lives?

• 25 years
• 200 years
• 400 years
• 800 years

Tags

CCSS.HSF.LE.A.4

How old is the Earth?

• 4.6 billion years
• 1.4 billion years
• 4.6 million years
• 6000 years

Tags

NGSS.HS-ESS1-6

The term given to unstable radioactive atoms.

• Parent

• Daughter

• Half Life

• Igneous

Tags

NGSS.HS-PS1-8

After one half life, a sample will begin to have more of the parent isotope than the daughter isotope.

• TRUE

• FALSE

Tags

NGSS.HS-PS1-8