question 1: A particular radioactive isotope decays from 180 milligrams (mg) to 151.2 mg in 7 days. Find the half life of the isotope.in days

question 2: The half-life of Palladium-100 is 4 days. After 16 days a sample of Palladium-100 has been reduced to a mass of 2 mg. What was the initial mass (in mg) of the sample?What is the mass 6 weeks after the start

question 3: You go to the doctor and he gives you 15 milligrams of radioactive dye. After 24 minutes, 7.5 milligrams of dye remain in your system. To leave the doctor's office, you must pass through a radiation detector without sounding the alarm. If the detector will sound the alarm if more than 2 milligrams of the dye are in your system, how long will your visit to the doctor take, assuming you were given the dye as soon as you arrived? Give your answer to the nearest minute.

question 4: A thermometer is taken from a room where the temperature is21 degree C to the outdoors, where the temperature is13 degree C. After one minute the thermometer reads9

.

(a) What will the reading on the thermometer be after3more minutes?

(b) When will the thermometer read12