Given the law of conservation of energy, what happens when a 200°C iron bar is placed in thermal contact with a 30°C block of wood? OA Energy leaves the iron bar and enters the wood until the temperatures are equal.
OB Energy leaves the wood and enters the iron bar until the temperatures are equal.
Ос All the energy from the iron bar is transferred to the wood.
OD All the energy from the wood is transferred to the iron bar.

  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-

that tool would be a compass

it is the most commonly accepted one

i wish i could but this one is weird give me abc and i can solve it.