Answer:
2 H2 + O2 => 2 H2O aka 2, 1, 2
Step-by-step explanation:
H2 + O2 => H2O
On the left side there are currently 2 H's and 2 O's
On the right side there are currently 2 H's and 1 O
We have to match both sides to equal the same number of H's and O's
As previously stated, both sides have 2 H's without doing anything to them so let's ignore that and skip to the O2
One the left there are 2 O's and on the right there is 1 O
We cannot remove O's so in order to equal each other we must look at the right side
To get from 1 O to 2 O, we can multiply H2O by 2
This will give us 4 H's, and 2 O's
This makes the O's equivalent to each other
But now, the H's are imbalanced
The left side has 2 H's while the right side has 4 H's
To make the 2 H's go to 4 H's, we multiply the 2 H's by 2
This gives us 4 H's on both sides and now the equation is balanced