Exponential Decay

What is Half-life?

• The amount of time it takes for some of the sample of the isotope to decay

• The amount of time it takes for half the sample of the isotope to decay

• the amount of time it takes to double the sample of the isotope to decay

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

The half life of iodine-131 is 8.040 days. What percentage of an iodine-131 sample will remain after 40.20 days?

• 312.5%
• 31.25%
• .3125%
• 3.125%

Tags

CCSS.HSF.LE.A.4

What is the half-life of iodine-131?

• 32 days

• 8 days

• 16 days

• 24 days

What percent of carbon-14 would be left after 5730 years?

• 100%

• 75%

• 50%

• 25%

Carbon dating can be used

• to determine the age of once living things up to 50,000 years ago

• to determine when the solar system was formed

• to determine the age of fossils from 65 million years ago

• to determine the age of the earth

An isotope is

• the same element with a different number of electrons

• the same element with a different amount of neutrons

• the same element with a different number of protons

• the same element, but isolated by itself

The age of the earth can be estimated by... (answer all that apply)

• carbon dating

• radioactive dating isotopes found on asteroids and the moon

• radioactive dating oxygen isotopes in zircon crystals found on Earth that cooled billions of years ago

• All of the above

• None of the above

May be more than one correct answer. Scientists support carbon dating evidence...

• by matching carbon dating to known dates from history, like the eruption of Pompeii

• by matching carbon dating to tree rings or layers of lake sediment

• by finding the differences in initial c14 amounts in aquatic organisms

• by researching c14 levels in the atmosphere and how they have changed over history

After two half lives, none of the parent (original) isotope will be left

• True

• False