How can phosphorus be isolated from its compounds?

Here we have to give a synthetic route to get phosphorous from its compound.

The reaction is:

2Ca₃(PO₄)₂ + 6SiO₂ + 10C → P₄ + 6CaSiO₃ + 10CO

Phosphorous occurs in nature as phosphorite [Ca₃(PO₄)₂], fluorapatite [3Ca₃(PO₄)₂.CaF₂].

The phosphorous is obtained by heating a mixture of phosphorite [Ca₃(PO₄)₂], silica [SiO₂] and coke (C) in an electric arc furnace at 1500⁰C. Phosphorous (P₄) is vaporize and leaves the furnace through an exit at the top.

It is condensed by cooling in  cold water and cast into sticks and stored under water. The fusible calcium silicate (CaSiO₃) is removed as side product.  

The reaction is:

2Ca₃(PO₄)₂ + 6SiO₂ + 10C → P₄ + 6CaSiO₃ + 10CO

geosphere and hydrosphere.

this is because the geosphere has to do with geological events, while the hydrosphere controls all water on earth.

answer:

the answer is 6 valence electrons.

explanation:

valence is the # of electrons on the outer most shell of an atom.

oxygen has 6.

although, the valency of oxygen is 2, because it only needs to make 2 covalent bonds, or gain 2 electrons, to achieve the stable octet configuration of a noble gas.

that's it!

if you need further assistance, let me know: )

~ trueboss72