4a. If there is 67.8% of the original amount of 238U, how long has it been around?

3. The most well-known type of radioactive dating is based on the decay of carbon-14, which decays via beta emission. Write the balanced reaction for the beta decay of 14C. The half-life for carbon-14 is 5730 years. 3a. Measurements on the linen wrappings from the Book of Isaiah in the Dead Sea scrolls suggest that the scrolls contain 79.5% of the 14C expected of living tissue. How old are the scrolls? (Provide your answer to this question, with units, for other team to write in the blank for 3b.) Write the balanced reaction for 238U alpha decay. The half-life of 238U is 4.51109 years. What percentage of the original 238U remains after