1) The mass of a radioactive substance is 1000g from the beginning and only 100g remains after 100 days. Determine the half-life, to one decimal place. 2) The San Francisco earthquake of 1989 measured 6.9 on the Richter scale. The Alaska earthquake of 1964 measured 8.5 on the Richter scale. How many times as intense was the Alaska earthquake compared to the San Francisco earthquake? Round your answer to the nearest integer