a. Bismuth-214 decays by alpha emission with a half-life of 19.7 minutes. If 15.0 grams of...

a. Bismuth-214 decays by alpha emission with a half-life of 19.7 minutes. If 15.0 grams of Bismuth-214 is placed in a sealed vessel, what mass of the Bismuth will have decayed after 35.0 minutes?

b. How long will it take for a sample of carbon-14 to decay such that only 70% of the original sample of carbon-14 remains?

c. In a process called "positron-electron annihilation," a positron collides with an electron, and both particles are destroyed. During this process, the total mass of both particles is completely converted to energy in the form of gamma radiation. Determine the total energy given off when one positron collides with one electron resulting in annihilation. (Note: mass of positron = mass of electron = 0.000549 amu)

Solutions

Expert Solution

c) Annihilation process makes two photons.

Let us assume the kinetic energy of each particle as 1.00 MeV.

The total energy of electron and positron is 2 × 1.00MeV + 2 × 0.511MeV = 3.02MeV . (Rest energy of electron is 0.511MeV .)

queen_honey_blossom answered 1 year ago

Next > < Previous

Related Solutions

81Sr decays by positron emission with a half-life of 22.2 minutes. Starting with 885g of Sr-81,...

81Sr decays by positron emission with a half-life of 22.2 minutes. Starting with 885g of Sr-81, how much remains after 75.0 minutes?

238Pu decays to 234U via alpha () emission with a half-life of 87.7 years; each ejected...

238Pu decays to 234U via alpha () emission with a half-life of 87.7 years; each ejected alpha particle has an energy of approximately 5.6 MeV. Estimate the (thermal) power produced by the rover RTG immediately after the construction of the RTG (with ‘fresh’ 238Pu). State clearly the key assumptions in your analysis.

The Plutonium isotope 239Pu has a half-life of 24,000 years and decays by the emission of...

The Plutonium isotope 239Pu has a half-life of 24,000 years and decays by the emission of a 5.2 MeV alpha particle. Plutonium is not especially dangerous if handled because the activity is low, and the alpha radiation doesn’t penetrate the skin. However, there can be serious health concerns if the tiniest particles are inhaled and lodge deep in the lungs. This could happen following any kind of fire or explosion that disperses Plutonium as dust. a) (3 pts.) Soot particles...

3816S decays by beta emission to 3817Cl. This reaction has a half‐life of 2.87 hours. The...

3816S decays by beta emission to 3817Cl. This reaction has a half‐life of 2.87 hours. The 3817Cl subsequently decays by beta emission to 3818Ar. This reaction has a half‐life of 37.3 min. a) How much will remain of an initially pure sample of 3.5 mg 3816S after 9.35 hours? b) How many mg of 3817Cl will be present after 9.35 hours? c) How many mg of 3818Ar will be present after 9.35 hours?

The half life of an isotope is 20 minutes. After 2.00 hours, 0.10 grams of the...

The half life of an isotope is 20 minutes. After 2.00 hours, 0.10 grams of the sample remains. how many grams was in the original sample.?

Fluorine-18 undergoes positron emission with a half-life of 1.10 x 102 minutes. If a patient is...

Fluorine-18 undergoes positron emission with a half-life of 1.10 x 102 minutes. If a patient is given a 248 mg dose for a PET scan, how long will it take for the amount of fluorine-18 to drop to 83 mg? (Assume that none of the fluorine is excreted from the body.)

The nuclide 236U decays with emission of an alpha particle with measured energy of 4.448 MeV...

The nuclide 236U decays with emission of an alpha particle with measured energy of 4.448 MeV and an accompanying gamma photon with measured energy of 49 keV. What is the product nucleus and does this particular decay of 236U occur to the ground state or and excited state of the product nuclide?

Polonium-218 is an alpha emitter with a half-life of 3.0 minutes. **)If a sample contains 55...

Polonium-218 is an alpha emitter with a half-life of 3.0 minutes. **)If a sample contains 55 mg of Po−218 (atomic mass = 218.008965 amu), how many alpha emissions would occur in 27.0 minutes? **)If the polonium were ingested by a person, to what dose of radiation (in Ci) would the person be exposed? (I need correct answer for this please)

Calculation of half-life for alpha emission using time-independent Schrodinger Equation using the following following information: Radionuclide:...

Calculation of half-life for alpha emission using time-independent Schrodinger Equation using the following following information: Radionuclide: 241-Am (Z=95); Ea = 5.49 MeV; Measured Half-Life~432y Follow the steps involved and show your work for each subset question, not the final answer: (a) Evaluate the well radius [=separation distance (r) between the center of the alpha particle as it abuts the recoil nucleus]; (b) Evaluate the coulomb barrier potential energy (U) for the well; (c) Estimate the separation distance (r*) from the...

Strontium-90 decays to Y-90 by beta decay with a half-life of 28 yrs. Y-90 decays by...

Strontium-90 decays to Y-90 by beta decay with a half-life of 28 yrs. Y-90 decays by beta decay-to Zircomium-90 with a half-life of 64 hrs. What is the composition of the original Strontium -90 sample after (a) 1 hr, (b) 10 yrs?

Subjects