Half Lives

Geologist use the time it takes for a radioactive isotope to decay to half its original mass called a___________.

• radioactive decay

• isotope

• half-life

• carbon dating

Tags

NGSS.HS-PS1-8

The half life of a sample is 5 days. How many half lives have passed in a period of 15 days?

• 1

• 2

• 3

• 4

What is the half life of this sample?

• 2 mins

• 3 mins

• 4 mins

• 4 hours

Tags

NGSS.HS-PS1-8

How old is this fossil after undergoing 4 half-lives?

Tags

NGSS.MS-ESS1-4

The amount of time it takes for half of the particles of an element to decay is called:

• Absolute Age

• Half-Life

• Radioactivity

Tags

NGSS.HS-PS1-8

Suppose you extract one gram of carbon from an ancient wooden hammer handle. You find that your ancient gram of carbon is half as radioactive as a gram of carbon extracted from a tree branch that was cut today. The half-life of C-14 is 5,730 years. Assuming that today’s ratio of C-14 to C-12 is the same as when the hammer was made, how old would you estimate is the hammer?

• 1,432.5 years old

• 2,865 years old

• 5,730 years old

• 11,460 years old

A 50.0 g sample of N - 16 decays to 12.5 g in 14.4 seconds. What is it's half - life?

• 14.4 sec

• 7.2 sec

• 3.6 sec

• 1.8 sec

Tags

NGSS.HS-PS1-8

The half - life of K - 42 is 12.4 hrs. How much of a 750 g sample is left after 62.0 hrs?

• 187.5 g

• 93.8 g

• 46.9 g

• 23.4 g

Tags

NGSS.HS-PS1-8

The time required for half of the parent isotope to decay into daughter isotopes.

• Absolute Age

• Relative Age

• Fossil

• Half-life

Tags

NGSS.HS-PS1-8

What is the half-life of a radioactive element?

• How old it is when it is middle aged

• The time it takes for half of the atoms to decay

• The time it takes for half of the atom to form

• How old it is when the Earth is middle aged

Tags

NGSS.HS-PS1-8