Questions from College Physics

Q: Radon gas has a half - life of 3.83 days

Radon gas has a half - life of 3.83 days. If 3.00 g of radon gas is present at time t = 0, what mass of radon will remain after 1.50 days have passed?

Q: A drug tagged with 4399Tc (half - life = 6.

A drug tagged with 4399Tc (half - life = 6.05 h) is prepared for a patient. If the original activity of the sample was 1.1 x 104 Bq, what is its activity after it has been on the shelf for 2.0 h?

Q: The half - life of 131I is 8.04 days.

The half - life of 131I is 8.04 days. (a) Convert the half - life to seconds. (b) Calculate the decay constant for this isotope. (c) Convert 0.500 μCi to the SI unit the becquerel. (d) Find the number...

Q: A neutral atom is designated as 4018X. How many (

A neutral atom is designated as 4018X. How many (a) Protons, (b) Neutrons, and (c) Electrons does the atom have? Answer: By convention, 1840X contains 18 protons and has a mass number of 40 so t...

Q: Tritium has a half - life of 12.33 years.

Tritium has a half - life of 12.33 years. What fraction of the nuclei in a tritium sample will remain (a) After 5.00 yr? (b) After 10.0 yr? (c) After 123.3 yr? (d) According to Equation 29.4a, an infi...

Q: After 2.00 days, the activity of a sample of

After 2.00 days, the activity of a sample of an unknown type radioactive material has decreased to 84.2% of the initial activity. What is the half - life of this material?

Q: After a plant or animal dies, its 14C content decreases with

After a plant or animal dies, its 14C content decreases with a half - life of 5730 yr. If an archaeologist finds an ancient fire pit containing partially consumed firewood and the 14C content of the w...

Q: A freshly prepared sample of a certain radioactive isotope has an activity

A freshly prepared sample of a certain radioactive isotope has an activity of 10.0 mCi. After 4.00 h, the activity is 8.00 mCi. (a) Find the decay constant and half - life of the isotope. (b) How many...

Q: A building has become accidentally contaminated with radioactivity. The longest -

A building has become accidentally contaminated with radioactivity. The longest - lived material in the building is strontium - 90. (The atomic mass of 3890Sr is 89.9077 u.) If the building initially...

Q: Chromium’s radioactive isotope 51Cr has a half - life of 27.

Chromium’s radioactive isotope 51Cr has a half - life of 27.7 days and is often used in nuclear medicine as a diagnostic tracer in blood studies. Suppose a 51Cr sample has an activity of 2.00 μCi when...