Half-Life and Nuclear Equations

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

When nuclei decay, massive amounts of __________ is released.

• energy
• jello
• protons
• neutrons

Tags

NGSS.HS-PS1-8

If the half-life of uranium-232 is 70 years, how many half-lives will it take for 10 g of it to be reduced to 1.25 g?

• 1 half-life
• 2 half-lives
• 3 half-lives
• 4 half-lives

Tags

CCSS.HSF.LE.A.4

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

• 1/2
• 1/3
• 1/16
• 1/8

Tags

NGSS.HS-PS1-8

What is the half-life of iodine-131?

• 32 days
• 8 days
• 16 days
• 24 days

Tags

NGSS.HS-PS1-8

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

NGSS.HS-PS1-8

What is the symbol for an alpha particle?

• ⁴₂He
• ⁰_-1e
• ⁰₊₁ e
• ¹₀n

Tags

NGSS.HS-PS1-8

This is the correct equation for U-238 decay.

• true

• false

Tags

NGSS.HS-PS1-8

Complete the nuclear equation and determine the type of decay that is occurring in this reaction. 

• alpha
• beta
• gamma
• none

Tags

NGSS.HS-PS1-8

This is the correct equation for the decay of Ra.

• true

• false

Tags

NGSS.HS-PS1-8