1. What is the frequency of x-ray radiation if the wavelength is 304.94 pm? This length
is about the size of an atom.
9.838e+15 s-1
9.838e+5 s-1
9.838e+17 s-1
9.838e+19 s-1

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).