In which orbitals would the valence electrons for selenium (se) be placed? a. s orbital and f orbitalb. s orbital onlyc. s orbital and p orbitald. d orbital only

It's actually D, s orbital and p orbitals

Option C = s orbital and p orbital  

Selenium's atomic number is 34, and it's in the fourth row in family VIA. The electron configuration of selenium is  

1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p4

The six electrons in the outermost shell allow selenium to have a variety of valence numbers. Selenium compounds have been found that have valences of -2, 4, and 6. Selenium is in the fourth period, so its valence electrons are in the fourth energy level. Selenium is in the oxygen family also known as group 16 therefore it has 6 valence electrons. It tries to gain two more electrons to get a full outer shell of eight electrons, when it does this it will have a negative 2 charge.

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).