New tab x and math121A_$700_1.pdf X + X Cn File D:/Math%20Sem1%20Final/math121A_$700_1.pdf Not syncing . .. 14 of 16 Q + STUDENT NUMBER: Section IX. Radioactive Dating [/8] The half-life of potassium-40, a radioactive isotope of potassium, is 1.25 billion years. Due to the volatility of the products of its radioactive decay, samples specifically of lava flow (a rock formation that was once liquid) can be measured, and the fraction of original vs. decayed potassium-40 can be used to date the lava flow. (a) Give a formula for the fraction of potassium remaining in a lava sample after & million years. + (b) A fossil has been found in an undisturbed rock layer, between two layers of old lava. Old Lava - 82.0% original potassium-40 present; 18.0% decayed Rock layer with fossil Old Lava 80.1% original potassium-40 present; 19.9% decayed Find the range of possible ages for the fossil. Give units in your answer. O'C 8:24 AM O Search ^ O ENG US 2022-12-02 Partly sunny