The half life of a certain substance is 28 years. how long will it take for a sample of this substance to decay to 78% of its orginal amount.

cock topography

the study of the surface of a large voluptuous cock.

look at that sorostitute right she's a cock topographer!

what classes are you taking this

cock topography!

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).