Which of the following chemical equations is balanced?

• A. 2 H_2 + O_2 ightarrow 2 H_2O
• B. H_2 + 2 O_2 ightarrow 2 H_2O
• C. 2 H_2 + 2 O_2 ightarrow 2 H_2O
• D. H_2 + O_2 ightarrow H_2O

Answer: (A)

Verified step by step guidance

1. Identify the number of atoms of each element on both sides of the chemical equation. For example, count hydrogen (H) and oxygen (O) atoms separately on the reactant and product sides.
2. Write down the atom count for each element on the reactant side and the product side. For instance, in the equation \$2\ H_2 + O_2 \rightarrow 2\ H_2O$, count how many H and O atoms are present on each side.
3. Compare the number of atoms of each element on both sides to check if they are equal. A balanced equation has the same number of each type of atom on both sides.
4. If the numbers are not equal, adjust the coefficients (the numbers in front of molecules) to balance the atoms. Remember, you can only change coefficients, not subscripts within chemical formulas.
5. Confirm that after adjusting coefficients, the total number of atoms for each element is the same on both sides, indicating the equation is balanced.