the compounds in which phosphorous posses the highest possible oxidation have to mention here.
The species in which phosphorous have the highest oxidation state are: H₃PO₄, P₂O₅, PCl₅
The possible oxidation state of phosphorous is III and V. The highest oxidation state is V. There are several compounds in which phosphorous posses the +5 oxidation state. Like- Phosphoric acid (H₃PO₄), phosphorous pentoxide (P₂O₅), Phosphorous chloride (PCl₅) etc.
The oxidation state of an element depends upon the valence electron the valence shell of phosphorous is 3s² 3p³. Thus there are 5 electrons, as it has vacant 3d orbital thus it can easily form compound having +5 oxidation state.
There are 6 neutrons in an atom of Boron
They are also called the noble gases or inert gases. They
are virtually unreactive towards other elements or compounds. They are found in
trace amounts in the atmosphere. Their elemental form at room temperature is
colorless, odorless and monatomic gases. They also have full octet of eight
valence electrons in their highest orbitals so they have a very little tendency
to gain or lose electrons to form ions or share electrons with other elements
in covalent bonds.
Answer:
is the change in enthalpy associated with the combustion of 530 g of methane.
Explanation:

Mass of methane burnt = 530 g
Moles of methane burnt = 
Energy released on combustion of 1 mole of methane = -890.8 kJ/mol
Energy released on combustion of 33.125 moles of methane :


is the change in enthalpy associated with the combustion of 530 g of methane.