Half Life

When the radioactive atoms in a sample decay by half...

• alpha decay

• Beta decay

• half-life

Tags

NGSS.HS-PS1-8

After every half-life, a radioactive atom is

• reduced by 50%

• decreased by 1/4

• increased by 1/2

Tags

NGSS.HS-PS1-8

Uranium238 take _________________for one half-life.

• 5730 years

• 20 billion

• 1.65 million

• 4.5 billion

Tags

NGSS.HS-PS1-8

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

The half - life of radon - 222 is 3.8 days. How much of a 100 g sample is left after 15.2 days.

• 50.0 g

• 25.0 g

• 12.5 g

• 6.25 g

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

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

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

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

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

Tags

NGSS.HS-PS1-7