Identification of a Substance by Physical Properties Part 1 - Determination of unknown solid
Metal #1
1. Mass of metal piece
Metal # 2
2. Volume of water
3. New volume of water with metal
4. Volume of metal piece (3-2)
5. Density of metal
VOITA
6. Type of metal
SHOW CALCULATIONS.

sure what is it? ^w^

the answer is learned

  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-

i think its 100.

hope this !