Chemistry questions?

1. What are the products in the fission if uranium-235 that make possible a nuclear chain reaction? 2. What is the purpose of placing control rods among uranium samples in a nuclear reactor?

Answers

pisgahchemist

Fission of U-235 ..... There are a number of possible fission fragments from the fissioning of U-235. But the important "left-overs" from the splitting apart of an atom of U-235 are neutrons (sometimes up to three per event). The neutrons go on to interact with other U-235 atoms causing them to undergo fission. The fission fragments are immaterial, it's the neutrons which make the chain reaction possible. -- See the diagram below. Control rods in a reactor absorb neutrons and regulate or even stop the fission process. Chain reaction - fission of U-235

lenpol7

1, 235_U = 231 - Th + alpha 231-Th = 231-Pa + beta(-) 231-Pa = 227-Ac + alpha 227-Ac = 223-Fr + alpha & 227-Th + beta 223-Fr = 223-Ra + beta(-) & 227-Th = 223-Ra + alpha 223-Ra = 219-Rn + alpha 219-Rn = 215-Po + alpha 215-Po = 211-Pb + alpha & 215-Po = 215-At + beta(-) 211-Pb = 211-Bi + beta(-) & 215-At = 211-Bi + alpha 211-Bi = 207-Tl + alpha & 211-Bi = 211-Po + beta(-) 207-Tl = 207-Pb + beta(-) & 211-Po = 207-Pb + alpha. That's the full disintegration series down to lead(207-Pb) ,which is not radioactive. Your correspondent ' pisgahchemist' has given a very good description of the use of control rods.

Was this article helpful?

Thank you! Your feedback will help us improve the support experience.

Chemistry questions?

Bauxite, the principle ore used in the production of aluminum cans, has a molecular formula of Al2O3•2H2O.?

Arrange from strongest to weakest attraction: a) polar and polar b) nonpolar and nonpolar c) polar molecule and ion d) ion and ion?