The decay of 40K to 40Ar is used to date igneous rocks around fossil deposits to bracket the age of the fossils. When 40K decays, 10.9% of the time it produces 40Ar. The half-life of 40K is 1.248 x 109 years. In a given rock sample, 281.8 nmol of 40K is measured and 7.25 nmol of 40Ar is measured. What is the age of the rock in years

answer is: naturally occurring solid, inorganic compound or element is mineral.

minerals usually have crystalline form, that means than crystal constituents (atoms, molecules or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions.

for example magnetite is a mineral of iron oxide (fe₂o₃).

calcite is a carbonate mineral and the most stable polymorph of calcium carbonate (caco₃).

dolomite is an   carbonate mineral composed of calcium magnesium carbonate (camg(co₃)₂).

answerto predict;

i believe the answer is 5,000