The half life of iodine-131 is 8.1 days. How long will it take for the sample to reduce to 1/4 its original amount?

Tags

NGSS.HS-PS1-8

How long would it take iodine to reduce to less than 1% its original amount?

• 50%

• 1.56%

• 100%

• 25%

• 12.5%

Uranium-238 decays very slowly, with a half-life of 4.47 billion years. What percentage of a sample of U-238 would remain after 13.4 billion years?

• 100%

• 50%

• 25%

• 12.5%

Tags

NGSS.HS-PS1-8

Uranium-238  decays into  Thorium-234  by emitting .........

• an alpha particle
• a beta particle
• gamma rays
• visible light

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

Solve Alpha/Beta

What is the change in the atomic number when an atom undergoes beta-minus decay?

• Increases by 1

• Decreases by 1

• No change

• Decreases by 2

Tags

NGSS.HS-PS1-8

What is likely to happen to unstable nuclei with too many, or too few, neutrons?

• They will decay by emitting radiation.

• They will loose all their electrons.

• They will bond with other atoms.

Tags

NGSS.HS-PS1-8

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

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