The designations s, p, d, f designate different types of electrons. a. valence electrons. b. different electron energy levels. c. different electron orbitals within an energy level.

C

Explanation:

The electrons in an atom are specifically housed in locations that could be referred to as shells. These shells are the places where we can find an electron.

Now, within each shell, we have different energy levels in which these occupants electrons occupy. These energy levels have different energies and the amount of electrons they can take.

For example, the number of electrons S can take is 2 while that in which d can take is 10

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).