1. Cesium-137 has a half-life of 30 years as it turns into a Barium-137. If you start with 931 grams of Cesium-137, how many grams do you have left after 86 years? Round your answer to the ones place.

2. Iodine-131 has a half-life of 8.0 days, as it decays into xenon-131. If you start with 985 grams of iodine-131, how many grams do you have left after 645 hours? Round your answer to the ones place.