Radon-222 has a half-life of 3.823 days. If a sample of pure radon-222 has an initial mass of 0.750 g, how much time is needed for only 0.100 g of radon-222 to remain?
Radon-222 decays by emission and is one of the largest sources of radiation exposure for many people.
Write a balanced equation for the decay of radon-222.
After 12.7 days, 90.0% of a sample of radon-222 has decayed. Calculate the half-life for the decay process.
Radon-222 is most hazardous if inhaled. Which properties of particles are responsible for this effect?
What is the half-life of a radioactive material?
The half-life of is years. What fraction of present today will be present in years, assuming no additional is formed?
The decay of 1.000 g of at 1 bar and 298 K produces mL of gaseous over 24 hours. Calculate the half-life of .
After 25.0 years, a 0.5000 g sample of contains only 0.0961 g of . Calculate the half-life of .
The half-life of is 6.0 hours. Calculate the rate constant for the decay of .
Technetium-99m has a half-life of 6.01 hours. How much time is needed for 85.0% of a sample of technetium-99m to decay?
Cobalt-60 decays to nickel-60 with a half-life of 5.27 years.
Calculate the decay constant for this process.
Calculate the fraction of a sample of cobalt-60 remaining after 15.0 years.
How much time is needed for 98.0% of a sample of cobalt-60 to decay?
A g sample of has a half-life of 5.52 hours.
Calculate the mass of after 70.0 minutes.
Calculate the percentage of remaining after 3.00 days.
How much time is needed for the sample mass to decrease to g?
The isotope undergoes decay with a half-life of 1.032 hours.
Which isotope is produced by the decay?
How much time is needed for 99.0% of pure to decay?
What percentage of a sample of pure remains after 4.30 hours?
What is the half-life of a radioactive material in terms of the rate constant for the radioactive decay, ?
Which of the following samples would have the greatest activity?
Iodine-131 decays with a rate constant of 0.138 d−1. Calculate the half-life for this decay.