PLEASE HELP!! Consider the following intermediate chemical equations.
C(s) + O2(g) → CO2(g) AH, --393.5kJ
2CO(g) + O2(g) → 2CO2(g) AH, --566.0kJ
2H2O(g) → 2H2(g)+O2(g) AH2 - 483.6 kJ
The overall chemical equation is C(s) + H2O(g) → CO(g) +H2(g). To calculate the final enthalpy of the overall chemica
equation, which step must occur?
Reverse the first equation, and change the sign of the enthalpy. Then, add.
O Reverse the second equation, and change the sign of the enthalpy. Then, add.
O Multiply the first equation by three, and triple the enthalpy. Then, add.
O Divide the third equation by two, and double the enthalpy. Then, add.

the grams   of   barium that   are in   2.3 x 10^23   atoms of barium   is   52.4 g (answer c)

    calculation

mass = moles   of ba   x molar   mass of ba

  molar mass of ba from periodic table=   137.3 g/mol

  use the   avogadro's law   constant   to   calculate the moles of barium

  that   is     1 mole =   6.02   x 10^23 atoms

                    ? moles = 2.3 x 10^23   atoms

by cross   multiplication

=(1 mole   x 2.3x 10^23 atoms)   / 6.02   x10^23 atoms)=   0.382   moles

mass   is therefore = 137.3   g/mol x 0.382 mol = 52.4 ( answer c)

explanation:

i don't know people like to fight everywhere rip.

it is stable as it is in group 0 which have full outer shells of electrons