Half-life Questions

Why are radioactive isotopes useful for dating?

• They always pay for dinner.

• They decay at a predictable rate.

• They have an internal arrangement of atoms.

• They always have a short half-life.

Tags

NGSS.HS-PS1-8

Which isotope would be best for finding the age of an ancient Egyptian mummy?

• Carbon-14

• Potassium-40

• Uranium-238

• Rubidium-87

What are 2 characteristics of an old tree stump that make it useful for dating with Carbon-14?

• It has a short half-life

• It was alive recently

• It was a living thing

• It is a solid substance

What happens to the half-life of Potassium-40 in a rock if you cut the rock in half?

• The half-life will be cut in half

• The half-life will stay the same

• The half-life will double

What happens to the half-life of Potassium-40 in a rock if you melt the rock?

• The half-life will be cut in half

• The half-life will stay the same

• The half-life will double

Tags

NGSS.HS-PS1-8

What happens to the half-life of Potassium-40 in a rock if 1.3 billion years have already passed?

• The half-life will be cut in half

• The half-life will stay the same

• The half-life will double

Tags

NGSS.HS-PS1-8

How old is a rock that has 1/2 of its Rubidium-87?

• 4.9 billion years

• 49 billion years

• 4.9 years

• 490 billion years

• 490 million years

How old is a rock that has 50% of its original Potassium-40?

• 1.3 billion years

• 13 billion years

• 130 million years

• 1.3 years

The Earth has approximately half of the amount of _____ that existed when it formed.

• Carbon-14

• Potassium-40

• Uranium-238

• Rubidium-87

What happens to Uranium-238 when it decays?

• It turns into dirt.

• It turns into lead.

• It disappears.

• It remains Uranium.

Tags

NGSS.HS-PS1-8