A radioactive substance has a decay rate of 0.079 per minute. How many grams of a 200 gram sample will remain radioactive after 1 hour? Round the answer to the nearest tenth of a gram, and do not include the unit in your answer.

A certain radio isotope has a half-life of 12 years. Find the mass that remains from a 220mg sample after 17yrs. Round to the nearest tenth.

There are initially 340 cells present in a colony of bacteria. This strain of bacteria grows by 22% every 3.5 hours. Assuming that this growth continues in this man- ner, determine the following. How many bacteria cells will be present in the colony after 24 hours? How long will it take for the colony to reach 5000 bacteria cells? Round each response to the nearest whole number. bacteria cells hours.

You are asked to make a 1/3 dilution using 1.5 mL of serum. How much diluent do you need to use?