Half Life

What is the half-life of Radon-222? 

• 1599 years
• 27.4 seconds
• 3.823 days
• 12.36 hours

Which isotope has a half-life of 5715 years? 

• Carbon-12
• Cobalt-60
• Carbon-14
• Cesium-137

Tags

NGSS.HS-PS1-8

What is Half-life?

• The amount of time it takes for some of the nuclei in a sample of the isotope to decay
• The amount of time it takes for half the electrons in a sample of the isotope to decay
• The amount of time it takes for half the nuclei in a sample of the isotope to decay
• the amount of time it takes to double the nuclei in a sample of the isotope to decay

Tags

NGSS.HS-PS1-8

The half-life of Zn-71 is 2.4 minutes. If one had 100.0 g at the beginning, how many grams would be left after 7.2 minutes has elapsed?

• 100.0g
• 50.0g
• 12.5g
• 8.5g

Tags

CCSS.HSF.LE.A.4

After the third half-life, how much of a radioactive sample is left?

• 1/2
• 1/3
• 1/16
• 1/8

Tags

NGSS.HS-PS1-8

The half life of iodine-131 is 8 days. What fraction of an iodine-131 sample will remain after 40 days?

• 1/2
• 1/64
• 1/5
• 1/32

Tags

NGSS.HS-PS1-8

As a sample of Neon-19 undergoes radioactive decay, its half-life will

• decrease
• increase
• remain the same
• start over

Tags

NGSS.HS-PS1-8

Barium-122 has a half-life of 2 minutes. A fresh sample weighing 80 g was obtained. If it takes 10 minutes to set up an experiment using barium-122, how much barium-122 will be left when the experiment begins?

• 0.25g
• 2.5g
• 25g
• 80g

Tags

CCSS.HSF.LE.A.4

The half-life of strontium-90 is 25 years. How much strontium-90 will remain after 100 years if the initial amount is 4.0 g?

• 3.0g
• 0.25mg
• 0.3g
• 0.25g

Tags

CCSS.HSF.LE.A.4

When nuclei decay, massive amounts of __________ is released.

• energy
• electrons
• protons
• neutrons

Tags

NGSS.HS-PS1-8