Arianna finds some fossil bones while digging in her backyard. could they be dinosaur bones? using carbon dating, she determines that 3% of the original radioactive carbon-14 is still radioactive. (the rest has decayed to nitrogen-14.) approximately how many half-lives have occurred? the half-life of carbon-14 is 5,730 years. this means that the animal died approximately years ago.

- approximately 5 half lives

- 28,650 years ago

Explanation:

After 1 half life:

50% gone, total gone = 50% and the amount that is left = 50%

After 2 half lives:

25% gone, total gone = 50 + 25 = 75% and the amount that is left = 25%

After 3 half lives:

12.5% gone, total gone = 87.5% and the amount that is left = 12.5%

After 4 half lives:

6.25% gone, total gone = 93.75% and the amount that is left = 6.25%

After 5 half lives:

3.125% gone, total gone = 96.875% and the amount that is left = 3.125%

Therefore, we can say that nearly 5 half-lives have occurred and the animal died approximately (5 x 5730 = ) 28,650 years ago.

Mechanical weathering breaks rocks into smaller pieces without changing their composition. ... Chemical weathering breaks down rocks by forming new minerals that are stable at the Earth's surface. Water, carbon dioxide, and oxygen are important agents of chemical weathering.

Explanation: