Question

in the equation $ch_4 + o_2 \to co_2 + h_2o$, what is unbalanced?
a. hydrogen atoms
b. carbon atoms
c. both hydrogen and oxygen atoms
d. oxygen atoms

Explanation:

Step1: Count carbon atoms

On left - hand side, in $CH_4$, there is 1 carbon atom. On right - hand side, in $CO_2$, there is 1 carbon atom. So carbon is balanced.

Step2: Count hydrogen atoms

On left - hand side, in $CH_4$, there are 4 hydrogen atoms. On right - hand side, in $H_2O$, there are 2 hydrogen atoms. So hydrogen is unbalanced.

Step3: Count oxygen atoms

On left - hand side, in $O_2$, there are 2 oxygen atoms. On right - hand side, in $CO_2$ there are 2 oxygen atoms and in $H_2O$ there is 1 oxygen atom, total 3 oxygen atoms. So oxygen is unbalanced.

Answer:

c. Both hydrogen and oxygen atoms