Question
Biology Question on evolution
Which of the following is relatively most accurate method for dating of fossils ?
A
Radio-carbon method
B
Potassium-argon method
C
Electron spin resonance method
D
Uranium-lead method
Answer
Electron spin resonance method
Explanation
Solution
Electron spin resonance (ESR) measures the number of charges occupying deep traps in the crystal bandgap. By measuring the change in absorption of microwave energy within a continuously varying strong magnetic field, this method detects the number of "'unpaired spins"" of electronic charges trapped at various" defects in the mineral lattice.