If we start with 16 grams of a radioactive substance, how much will remain after three half-lives

Can someone check my work 98 5.05 acids and bases for this assignment you will be comparing acids and bases. the chart below will you organize the information needed: acids bases chemical properties (2) deodorant detergent vinger dish soap physical properties (2) orange juice toilet cleaner drain cleaner window cleaner ph level acid ph goes from 0-4 bases ph goes from 10-14 examples around you (2) vinger coffee lemon juice dark chocolate