isotopes 1 Flashcards
definition of isotope
atom of the same element that the same p+ and e- but a different n
stable : do not decay
radioactive: decay spontaneously
stable isotopes uses
- isotope fractionation gives info about geoX processes taking place in a syst
- trace origine of elts from diff sources
radioactive isotopes uses
- used to trace the origin of elts from diff sources
- used to date geological materials (age)
vibration frequency of atoms
lower for heavy atoms (stronger bond)
higher for light atoms (weak bond)
differences btw light and heavy isotopes
isotopes in gases : light diffuse faster and more reactive than heavy
isotope fractionation
cause a change in relative proportions btw isotopes
independant of dilution!
biochemical processes that affect isotope fractionation
-redix transformation
complexation
sorption
precipitation
dissolution
evaporation
diffusion
biological cycling
description of isotope data
a=Ra/Rb
=(deltaA+1000)/(deltaB+1000)
deltaR=(Rsample/Rstandart-1)*1000
assumptions a : isotopic eq btw phases, in ocean evap and cond=, cst T°