Ok the question is some what simple and difficult. I know there are certain rules like a. A + B = AB (combination) b. AB = A + B (decomposition) c. AB + C = CB + A (substitution) d. AB + CD = AD + CB (metathesis) now the trouble i have is not in balancing the equation but figuring out what the out come of the reactants will be. For example an unsolved and unbalanced equation. ___Ca(s) + ____H2O(l) ----> (???) Why is the answer to the above question Ca(OH)2 + H2 and not CaO + H2.......are there any particular rules i would have to know when figuring out the product of reactants. Using the rules mentioned above would the following equation be right or wrong ___Al(s) + ____H2O(l) ----> (???) result: 2Al + 3H2O ---> Al2O3 + 3H2 Also is there anything to do with classification of elements that change the out come of the product. Thanks!!!