Nuclear Half Life

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

NGSS.HS-PS1-8

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

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

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

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

CCSS.HSF.LE.A.4

Gamma rays damage human cells/tissue.

• True
• False

Tags

NGSS.HS-PS4-4

When nuclei decay, massive amounts of __________ is released.

• energy
• jello
• protons
• neutrons

Tags

NGSS.HS-PS1-8

When an element loses protons, its __________changes.

• protonic number
• electronic number
• neutronic number
• atomic number

Tags

NGSS.HS-PS1-8

What makes an element radioactive?

• When it's nuclei expands
• When it's electrons explode
• When it's nuclei behave
• When it's nuclei decay

Tags

NGSS.HS-PS1-8