Phosphorus-32 has a half-life of 14.3 days. What is the first-order rate constant for the decay of this isotope?

Oxygen-22 disintegrates into Fluorine with a decay rate of  λ = 0.315 per seconds. Considering an initial amount of Oxygen 22, which percentage of it will be left after 5.8 seconds? Keep three significant digits.

If 28.0% of a sample of technetium-99 decays in 2.84 hours, what is the half-life of this isotope (in hours)?

Copper(II) acetate containing copper-64 is commonly used to study brain tumors. This isotope has a half-life of 12.7 hours. a. What is the rate constant for the decay of Cu-64? b. If initially there is 118 mg of Cu-64, what mass remains after 424 hours?

The first-order decay of iron-59 has a half-life of 44,495 days. How many grams of iron-59 decompose after one month (assume it is in April) if the sample initially weighs 100.0 g?

Iodine-131 is a radioactive isotope that is used to diagnose and treat some forms of thyroid cancer. Iodine-131 decays to xenon-131, according to the equation below. iodine-131 → xenon-131 + electron The decay is first order with a rate constant of 0.138 d-¹. All radioactive decay is first order. How many days will it take for 18.0% of the iodine-131 in a 0.500 M solution of this substance to decay to xenon-131? Select the correct answer below: 0.0594 day 1.30 days O 1.44 days 12.4 days MOICH

radioactive Cs-131 is used to treat tumors by implementation directly in the tumor site. The radioactive decay of Cs-131 is first order with t1/2=9.7 days. If the tumor is implanted with Cs-131, how long will it take for 33% of the Cs-131 to be left in the tumor?