The half life of carbon 14 is 5700 years. If the carbon 14 level measured in a fossilized bone has only 1/4 of the original amount, how old in the bone?
8550
The answer is 10 grams.
To determine the age of the fossilized bone, we can use the concept of radioactive decay and the half-life of carbon-14.
The half-life of carbon-14 is the amount of time it takes for half of the atoms in a sample to undergo radioactive decay. In this case, the half-life of carbon-14 is 5700 years, meaning that after 5700 years, half of the carbon-14 atoms in a sample will have decayed.
Given that the carbon-14 level in the fossilized bone is only 1/4 of the original amount, we can surmise that three half-lives have passed since the bone was alive:
Original amount → 1/2 → 1/2 → 1/2 → 1/4
Since each half-life is 5700 years, the total elapsed time is:
5700 years (1st half-life) + 5700 years (2nd half-life) + 5700 years (3rd half-life) = 17100 years
Therefore, the fossilized bone is estimated to be approximately 17100 years old.
50% 1/2 = 5700 (one half life)
25% 1/4 = 5700 x 2 (two "half life"s)
Therefore, after two complete half life cycles, there will be only 1/4 of the original amount.