Absolute Dating

Scientists use radioactive decay to measure...

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

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

• era
• age
• half-life
• eon

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

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

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

Relative Dating dates rocks __________
Absolute Dating dates rocks __________

• exact age; sequence
• sequence; exact age
• exact age; parent isotopes
• Laws; Isotopes

The original element that undergoes radioactive decay is known as the...

• daughter element
• half-life
• parent element
• carbon-14

What percent of carbon-14 would be left after 5730 years?

• 100%
• 75%
• 50%
• 25%

Tags

CCSS.HSF.LE.A.4

What percent of carbon-14 would be left after 11,460 years? (2 half lives)

• 100%
• 75%
• 50%
• 25%

Tags

CCSS.HSF.LE.A.4