22. A student carefully measures a certain quantity of four different substances into trays that will be used in a laboratory exercise. Which of these trays would
contain the largest number of atoms?
Sample
Mass of tray
with sample
Water
Mass of
empty tray
37.86g
36.59g
37.418
55.88g
Table Salt (NaCl)
Copper Wire
95.03g
100.96g
245.20g
Lead Shot
38.08g

Water

Explanation:

  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-