Nuclear chemistry Questions and Answers

a. S decays via ß particle emission with a half-life of 87.5 days. Complete the decay reaction. Write the isotope produced as (Write the mass number, atomic number, and symbol for the particle.) b. If a sample contains 3.80 g of 16S, what mass of that isotope remains after 175 days? Half-life = 87.5 days

In a hydrogen atom, if an electron absorbs 40.88 x 10-20 J of energy and originated at a relaxed energy level n=2, then which level was it excited to n = ? Answer in whole numbers only as there is not a 1.5 energy level for example.

An unknown element has two stable isotopes. 92.41 percent of all atoms of this element have a mass number of 7. The remaining 7.59 percent of atoms of this element have a mass number of 6. Which of the following is MOST LIKELY to be true about the average atomic mass of the unknown element? a The average atomic mass is slightly lower than 7 but much higher than 6. b The average atomic mass is 6.5 C The average atomic mass is slightly higher than 6 but much lower than 7. d There is no way to estimate the average atomic mass without knowing the identity of the element.

A sample has 1500 radioactive particles in it today. This same sample had 12000 radioactive particles in it 30 years ago. How many radioactive particles will be present in another 10 years?

Determine the half-life (in hours) of the radioactive isotope, Pb-212. A sample of pure Pb-212 was placed on a benchtop. After 33 hours, 12.5% of the original Pb-212 remains.

A local FM radio station broadcasts at an energy of 6.30x10-29 kJ/photon. Calculate the frequency at which it is broadcasting. (1 MHz = 106 sec -¹)

The energy of a photon needed to cause ejection of an electron from a photoemissive metal is expressed as the sum of the binding energy of the electron plus the kinetic energy of the emitted electron. When photons of 4.00x107 m light strike a calcium metal surface, electrons are ejected with a kinetic energy of 6.26×10-20 J. a Calculate the binding energy of the calcium electrons. b The minimum frequency at which the photoelectric effect occurs for a metal is that for which the emitted electron has no kinetic energy. Calculate the minimum frequency required for the photoelectric effect to occur with calcium metal.

What particle is needed to complete the following nuclear equation?

Match the description of the nuclear decay particle with the name. A mass number of 0 with a nuclear charge of -1 A +1 nuclear charge and a mass number of 0 Identical to a helium nucleus; mass number is 4 and nuclear charge is +2

A sample of a material has 40000 radioactive particles in it today. Your mother measured 80000 radioactive particles in it 30 years ago. How many radioactive particles will the sample have 30 years from today? How many radioactive particles will the sample have 60 years from today?

Select the true statements about alpha particles. Alpha particles have a nuclear charge of +1. Alpha particles have a mass number of 4. Alpha particle formation is accompanied by the conversion of a proton into a neutron. Alpha particle formation is accompanied by the conversion of a neutron into a proton.

The half-life of radioactive chromium-51 is 28 days. If a sample of chromium-51 has a mass of 12.0 µg, calculate the number of days it will take for the mass to be reduced to 1.50 µg.

A 2-cm thick piece of cardboard paper is placed over a radiation source would be most effective in protecting against which type of radiation? Alpha because it emits an electron. Gamma because waves can be stopped by paper. Alpha because it contains a larger particle.

A scientist is studying a newly discovered element, Tellpunium, in the lab. Based on the data she has collected, an originally 62.3 gram sample decayed to a mass of 0.44 grams after 78 miniutes had passed. Based on this information, calculate Tellpunium's half-life. Round your answers to 2 decimal places.

Calculate the binding energy, and the binding energy per nucleon, for a nucleus of the 238 U isotope. Express your answers in units of megaelectronvolts (MeV).

Calculate the radiation dosage in grays for a 69-kg person who is exposed for 3.0 s to a 3.0 Ci source of beta radiation. Assume that 100% of the radiation is absorbed and that each beta particle has an energy of 1.8 x 10-13 J.

Select the true statements regarding gamma rays. Gamma rays have a nuclear charge of -1. Gamma rays have a mass number of 0. Gamma rays have a nuclear charge of +1. Gamma rays are streams of high-energy photons.

210 pb has a half-life of 22.3 years and decays to produce 206 Hg. If you start with 6.52 g of 210 Pb, how many grams of 206 Hg will you have after 15.7 years? 2.47 g 4.00 g 8.01 g 2.00 g 12.8 g

What are the three kinds of radioactive decay? Adam, beta, and gamma Alpha, beta, and delta Alpha, beta, and gamma Alpha, bravo, and gamma

What is the daughter nucleus (nuclide) produced when 213 Bi undergoes alpha decay? Replace the question marks with the proper integers or symbols.

Gold-198 has a half-life of 2.7 days. How much of a 532.8 mg gold-198 sample will remain after 13.5 days?

The half life for the decay of carbon-14 is 5.73 x 10³ years. Suppose the activity due to the radioactive decay of the carbon-14 in a tiny sample of an artifact made of wood from an archeological dig is measured to be 7.0 x 10³ Bq. The activity in a similar-sized sample of fresh wood is measured to be 8.9 x 10³ Bq. Calculate the age of the artifact. Round your answer to 2 significant digits.

The experimentally determined atomic mass of Na-23 is 22.98977 amu. Calculate the mass defect, the binding energy in J/mol the binding energy in MeV/atom.

Complete the balanced equation for the nuclear decay of cobalt-65 by filling in the missing charges, mass numbers, and symbols below.

A laboratory investigation shows that a sample of uranium ore contains 6.82 mg of 325U (molar 92 mass 238.05079 g/mol) and 3.06 mg of 29 Pb (molar mass 205.97447 g/mol). Calculate the age of the ore. The half-life of 33 U is 4.5×109 yr.

The half life for the decay of carbon-14 is 5.73 x 10²³ years. Suppose the activity due to the radioactive decay of the carbon-14 in a tiny sample of an artifact made of wood from an archeological dig is measured to be4.7 x 10³ Bq. The activity in a similar-sized sample of fresh wood is measured to be 7.0 × 10³ Bq. Calculate the age of the artifact. Round your answer to 2significant digits.years