Science 10-Half Life Assignment

Half-life

The time required for half of a sample of a radioactive substance to decay or transform into a different substance. It is a key concept in nuclear chemistry and radioactive dating.

How long is one half-life of carbon-14?

Approximately 5,730 years.

What is the percentage of carbon-14 after one, two, and three half-lives?

50% after 1 half-life, 25% after 2, and 12.5% after 3

Estimate the percentage carbon-14 after 5000 years, 10000 years, and 15000 years

Approximately 87%, 75%, and 62.5%

Use the graph to estimate number of years based since the organism died if the percentage of parent isotope that remains is 40%, 20%, 5%

Approximately 8,000 years for 40%, 14,000 years for 20%, and 22,000 years for 5%.

Why is carbon-14 half-life measurements are not effective in dating an organism that has been dead for more than 50,000 years

Because after this time, the amount of carbon-14 remaining is so minimal that it becomes difficult to accurately measure, leading to unreliable dating results.