In the fall of 2002, a group of scientists at Los Alamos National Laboratory determined that the critical mass of neptunium-237 is about 60.0kg. The critical mass of a fissionable material is the minimum amount that must be brought together to start a chain reaction. Neptunium-237 has a density of 19.5g/cm3. What would be the radius rr of a sphere of neptunium-237 that has a critical mass?

Suppose you are working as a reactor operator in the world’s largest nuclear power station at Kashiwazaki-Kariwa Nuclear Power Plant, Japan. The first unit in this station began to operate in 1985. Suppose the rate at which the nuclear power plant produces radioactive waste is proportional to the number of years it has been operating such that 500 pounds of waste is produced every year. Also, suppose that the waste decays exponentially at a rate of 5% per year. At the beginning of 2011, The Fukushima Daiichi nuclear disaster caused sever damages in the units which released the radiation waste to the atmosphere. Therefore, all the units were closed in 2011 for safety inspection. This left japan completely without nuclear-produced electrical power. Finally, the unit began to operate at the beginning of 2019. As a reactor operator, you are asked to do the following: a. Model the generation of the Kashiwazaki-Kariwa Nuclear Power Plant radioactive waste as a function of time. b.…

One of the nuclear fission reaction that can happen in a nuclear reactor is the fission of Uranium-235 into Rubidium- 96 and Cesium-137 as shown below. The atomic mass of U-235 is 235.043930 u, the atomic mass of Rubidium is 95.93427 u, the atomic mass of Cesium-137 is 136.90709 u, and the mass of a neutron is 1.008665 u.  Determine the amount of energy released by the reaction, expressed in MeV. Keep five significant digits.

Nuclear matter is extremely dense. (a) Calculate the density, in kg/m³, of A neutrons in a sphere of radius r = ro 4¹/3, where ro = 1.2 x 10-¹5 m. (b) Find the diameter of a sphere of nuclear matter that would have the same mass as the earth. The average radius of the earth is 6.4 x 106 m and the average density of the earth is 5.5 x 10³ kg/m³.

Nuclear Physics - Nuclear Structure Density= Nuclear Structure Z mass Volume radius r=r04¹/3 ro=1.2x10-¹5 m N A = Z+N 4 The radius r of a nucleus is given in the above figure. The volume of a nucleus is V = Proton 56 Fe nucleus has a total of 56 nucleons (protons + neutrons). The average mass of a nucleon is u = 1.66x10^-27 kg I whin ber Neutron A Z If this unknown nucleus has 60 neutrons, how many protons does it have? Enter a number rr³ (a)Calculate the radius of a 56 Fe nucleus. Write the radius in fm, 1 fm = 10-15 m. Keep 2 decimal places. Enter a number x10-¹5m, fm (b) Calculate the Denisity of a 56Fe nucleus.. Write the result in terms of 1017 kg/m³. Keep 2 decimal places. Enter a number x10¹7kg/m³ () (c) An unknown hacieus has twice the volume of 56Fe. What is the mass number A of this nucleus? Enter a number i

Estimate the radius of a sphere that would hold all of a person's mass if its density equaled the density of a nucleus. Suppose that the mass is 70 kg and the density of the nucleus is 2.4 x 1017 kg/m³. Express your answer with the appropriate units.

Density is the ratio of mass to volume. If a uranium nucleus has a radius of 7.4 femtometers and nuclear mass of 238 AMU, what is its density in kg/m3? Assume the nucleus is sphere-shaped to find its volume.

NUCLEAR CHEMISTRY: Consider the nuclei Sn with an atomic number of 50 and mass number is 117 . Determine its mass defect in kilograms if its atomic mass is 116.956 amu. The mass of a proton and neutron are 1.0073 and 1.0087 amu, respectively. Express your answers in three decimal places in scientific notation, i.e., 6.022e23 to represent 6.022x 105

Plutonium-239 (atomic number 94) is a by-product of nuclear power plants. It decays via alpha and gamma decay. The half-life for the decay is 24100 years. What is the decay constant for Pu-239 expressed in inverse years and inverse seconds? If the sample of Pu-is measured to have an activity of 150 decays per second today, how many years would it take for the sample to reduce to an activity of 5 decays per second? How many Pu-239 nuclei are in the sample measured today?

Learning Goal: Radioactive decay - Half-life N 1,000,000 500,000 250,000 125,000 62,500 Number of nuclides, N x 10³ 1000 750 500 250 125 0 Time 0 the 2012 3h2 4112 5h2 612 7h2 8h2 9412 10₁2 31,250 15,625 he 2h 3h 4h 5h 6h 7he 8he 9h 10h Time in multiples of f 7,813 3,906 1,953 977 A radioactive sample's half-life is 30.2 years. 1 year = 365 days, 1 day = 24 hours, 1 hour = 60 min, 1 min = 60 s