Key Terms
Nuclear chemistry
The study of reactions that involve changes in nuclear structure. Chemical reactions change electron arrangements; nucle
Nucleus
Contains protons and neutrons (collectively called nucleons).
Nuclide
A specific type of nucleus, written as X-A (e.g., carbon-14).
Atomic number (Z)
Number of protons. Mass number (A): protons + neutrons.
Mass defect
The difference between the calculated mass of a nucleus (sum of its parts) and its actual measured mass. The "missing" m
Binding energy
The energy required to break a nucleus into its individual protons and neutrons. Equals the energy released when those n
FORMULA
E = mc^2 (Einstein's mass-energy equivalence)
Energy units
1 electron volt (eV) = 1.602 x 10^-19 J Nuclear binding energies are typically expressed in MeV (megaelectron volts).
Steps
Find mass defect in amu, convert to kg, apply E = mc^2, convert to MeV if needed (1 eV = 1.602 x 10^-19 J; 1 MeV = 1.602
Example
U-235 absorbs a slow neutron, forms unstable U-236, which splits into barium-141 and krypton-92 plus 2-3 neutrons.
Two conservation laws must both hold
1. Sum of mass numbers (A) is conserved.
Relationship between lambda and half-life
Lambda = 0.693 / t-1/2
Or equivalently
Ln(N-t / N-0) = -lambda * t
LIMITATION
Fossil fuel combustion has added CO-2 with essentially no C-14 (it has long since decayed), diluting the atmospheric rat
Five essential components
1. Nuclear fuel: enriched uranium (about 5% U-235 vs.