Using this method answer these questions

er parent or daughter isotopes in the rock following its formation. This can be done in several ways, most commonly through the adding of heat and pressure (metamorphism). There are ways to correct for these issues that allows the scientist to date both the rock and the metamorphic event as long as the geologic history is known. As you may have guessed from the previous exercise, it is rare to find a rock that contains an amount of the parent remaining that falls exactly on one of the half-lives. In most cases we need to use a simple formula to calculate the age of a rock using the length of the half-life and the amount of parent remaining. The formula is: Age - -(41/2 ) In(P) 0.693 t1/2 = The length of the half-life in years P = The amount of the parent remaining in decimal form. For example, if there is 50% of the parent remaining it would equal o.5. Let's work an example using the equation that we already know the answer to in advance. You have a sample of bone that has 25% of the Carbon-14 (Half-life= 5730 years) remaining, how old is the sample? We can answer this question in two ways: 1. We know that if there is 25% remaining, two half-lives have passed and with each half-life being 5730 the bone would be 11,460 years old. 2. We could use the above equation and insert both the length of the half- life and the amount of the parent remaining: 5730 Age =- 0.693 )In(0.25) To solve the equation, take the Natural Log (In) of 0.25 and multiply by the term in the parentheses (make sure to include the negative sign). If you do this you will get 11,460 as well. Page | 17