Arianna finds some fossil bones whip 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 reef 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.

After 1 half-life: 50% gone. Total gone = 50%.  Amount left = 50%

After 2 half-lifes: 25% more gone. Total gone = 75%. Amount left = 25%

After 3 half-lifes: 12.5% more gone. Total gone= 87.5%. Amount left= 12.5%.

After 4 half-lifes: 6.25% more gone. Total gone= 93.75%. Amount left= 6.25%

After 5 half-lifes: 3.125% more gone. Total gone= 96.875%. Amount left= 3.125%.   Here we are !

Looks like right around 5 half-lifes have passed.

(5 half-lifes) x (5,730 years/half-life) = around 28,650 years .

= = = = = = = = = =

After 1 half-life: 1/2 gone. Total gone = 1/2. Amount left = 1/2.

After 2 half-lifes: 1/4 more gone. Total gone = 3/4. Amount left = 1/4.

After 3 half-lifes: 1/8 more gone. Total gone= 7/8. Amount left= 1/8.

After 4 half-lifes: 1/16 more gone. Total gone= 15/16. Amount  left= 1/16.

After 5 half-lifes: 1/32 more gone. Total gone= 31/32. Amount left= 1/32 = 3.125%.   Here we are !

Looks like right around 5 half-lifes have passed.

(5 half-lifes) x (5,730 years/half-life) = around 28,650 years .

the answer for apex is the lowest

what experimental evidence led scientists to change from the previous model to this one?

a few of the positive particles aimed at a gold foil seemed to bounce back.

the colors of light emitted from heated atoms had very specific energies.

experiments with water vapor showed that elements combine in specific proportions.

cathode rays were bent in the same way whenever a magnet was brought near them.