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

What is the only difference between two different isotopes of the same element?

• Number of neutrons

• Number of protons

• Number of electrons

• Size of atom

Tags

NGSS.HS-PS1-8

The % of the parent isotope remaining after 1 Half Life.

• 50%

• 25%

• 12.5%

• 6.25%

Tags

NGSS.HS-PS1-8

The % of the parent isotope remaining after 2 Half Lives.

• 50%

• 25%

• 12.5%

• 6.25%

Tags

NGSS.HS-PS1-8

The % of the parent isotope remaining after 3 Half Lives.

• 50%

• 25%

• 12.5%

• 6.25%

Tags

NGSS.HS-PS1-8

You have 100 grams of radioactive C-14. The half life of C-14 is 5730 years. 
How many grams are left after 1 half life? 

• 100 grams
• 25 grams
• 2 grams
• 50 grams

Tags

CCSS.HSF.LE.A.4

If the half life of a radioactive element is 100yrs, how long would it take for the radioactivity to reduce by one half?

• 200yrs

• 100yrs

• 50yrs

• 300yrs

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 4.8 minutes has elapsed?

• 100.0g

• 25.0g

• 12.5g

• 8.5g

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

• 25.0g

• 12.5g

• 8.5g

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