Radiometric Dating

Which is NOT a method to date the oldest earth rock, mars rock, moon rocks, or meteors?

• Stratigraphic layering

• Crater density

• radiometric dating

• tree rings

When does radioactive decay occur?

• When the nucleus of an isotope is unstable
• When the nucleus of an isotope is stable
• When the electrons of an isotope are spinning
• When the electrons of an isotope are shared with another isotope

An atom with a different number of protons and neutrons

• electrons

• isotopes

• ions

• reaction partners

How many grams of Carbon-14 will remain after 17,100 years- C-14 has a half life 5,730 so 17,100 is about 3 half lives?

• 32 g

• 16 g

• 8 g

• 4 g

How many half-lives have passed if 12.5% ¹⁴C remains?

• 1 Half-life

• 2 Half-lives

• 3 Half-lives

• 4 Half-lives

What percentage of Rubidium-87 will remain after 4 half-lives?

• 25%

• 12.5%

• 6.25%

• 3.125%

The shaded boxes represent the undecayed atoms for Isotope "X". If Isotope X has a half-life of 1,000 years, how old is this sample?

• 1,000 years

• 2,000 years

• 3,000 years

• 4,000 years

When an unstable radioactive atom decays, it usually turns into:

• a more radioactive atom

• a more stable atom

• the exact same atom but with less pure energy

• empty space

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