1. 1.204 x 1024 atoms he = ? moles he

Check your chemistry textbook (or class notes) concerning molar mass, then look up the value for oxygen.

Then divide Avogadro’s number into the given amount of atoms, to find the number of moles.

Then combine this result appropriately with the molar mass, and voilà!

…Then reconsider posting homework questions without showing the work you have already done.

  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-

your answer would be “dry”