Pls help me identify which of these substance are a physical change or a chemical change . BAKING A CAKE
SETTING OFF A FIREWORK
BOILING WATER
BAKING BREAD DISSOLVING SUGAR IN TEA
MAKING WINE FROM GRAPES AND YEAST
MAKING CONCRETE FROM SAND CEMENT AND WATER

  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-

football

explanation:

because it is