Using absolute dating,a fossil is dated to be 3 million years old and decomposed 1 half-life. If it takes the same fossil 12 million years to decompose to 4 half-lives,how old will the fossil be when it is measured to be at 3half-lives?
To solve this, we need to understand the concept of half-life and how it can be used to estimate the age of a fossil using absolute dating.
The half-life of a radioactive substance is the amount of time it takes for half of the substance to decay into a stable form. In this case, let's assume the fossil contains a radioactive substance with a known half-life.
Given that the fossil is dated to be 3 million years old and decomposed 1 half-life, we can conclude that the half-life of the radioactive substance in this particular fossil is 3 million years. This means that it takes 3 million years for half of the original radioactive substance to decay.
Now, if it takes 12 million years for the same fossil to decompose to 4 half-lives, we can determine the total age of the fossil. Since each half-life is 3 million years, 4 half-lives would be equal to 12 million years.
To find the age of the fossil when it is measured at 3 half-lives, we can simply divide the total age (12 million years) by the number of half-lives (4) to get the age per half-life. In this case, 12 million years divided by 4 is equal to 3 million years per half-life.
Since we want to know the age at 3 half-lives, we can multiply the age per half-life (3 million years) by 3. Therefore, the fossil will be approximately 9 million years old when it is measured to be at 3 half-lives.
In summary, when the fossil is measured at 3 half-lives, it will be approximately 9 million years old.