Nuclear Equations and Half Life problems

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

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

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

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

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

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

The diagram shows 32 atoms.

16 of the Red are parent isotopes

16 of the Green are daughter isotopes

How many half-lives have occurred?

• 0

• 1

• 2

• 3

Tags

NGSS.HS-PS1-8

What type of decay is being illustrated in following picture? 

• beta decay
• alpha decay 

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

NGSS.HS-PS1-8