In the molecule PCl3PCl3, phosphorus makes three covalent bonds. Therefore, three of its five valence electrons need to be unpaired. The orbitals with the same energy are known as degenerate orbitals. For example, the p subshell has three degenerate orbital, namely, pxpx, pypy, and pzpz. How many degenerate orbitals are needed to contain five electrons with three of them unpaired?

  the   balanced   equation   for   reaction of   ca metal   with   o2 to   produce   cao   is as below

2 ca+ o2→ 2 cao2

  explanation

the reaction is   balanced     since the   number of atoms   in reactant side is   equal to   number of atoms   in   product side.   for   example   they   are 2   atom of   ca in   reactant   side   and   2   atoms of ca   in   the product side.

  the   process   is a   meet the   requirement   of   redox   reaction because :     calcium   is   oxidized   from   oxidation state 0   to 2+   while   oxygen   is reduced from   oxidation   state   0   to 2-