Ca(s) + O₂(g)→ 2 CaO (s)
The sequence of coefficient that will balance the above equation is
2,1 ,2
Explanation
Coefficient is the number in front of the formulas.
When balancing the equation the number of atoms in reactant side must be equal to number of atoms in product side.
The sequence that balance the equation above is 2,1,2 therefore the balanced equation is as below.
2Ca (s) + O₂ → 2CaO (s)
