A uranium-lead age determined from a zircon crystal removed from a sandstone would reflect the time elapsed since the ________ of the zircon.
A) erosion
B) deposition
C) crystallization
D) cementation
Question 2
In order to use a radioactive-decay scheme to calculate the age of a mineral all of the following conditions must be met except
A) the half-life must be known.
B) no daughter isotope present prior to the start of parental decay or the amount of daughter can be determined.
C) no parent or daughter isotopes can be gained or lost from the mineral once decay starts.
D) only one radioactive isotope can exist in the rock so that cross-decay doesn't occur.
Transdermal patch administration: (a) protective coating removed from patch
Transdermal patch administration: (b) patch immediately applied to clean, dry, hairless skin and lab
Bronfenbrenner’s model of the ecological-systems approach to studying development. He suggested that
Running time on 100-meter sprint for men and women master athletes increases with age. Source: Korho
Comparison of de novo predictions to X-ray crystal structures
Mutagenicity of aflatoxin B1 determined by the Ames test