Question

Use the chemical reaction to answer the question.

2H2+O2→2H2O

There are four atoms of hydrogen ( H
) before the reaction. How many atoms of hydrogen are present after the reaction?

Answer 1

In the chemical reaction given:

\[ 2H_2 + O_2 \rightarrow 2H_2O \]

There are four hydrogen atoms on the left side (2 molecules of \( H_2 \) means \( 2 \times 2 = 4 \) hydrogen atoms).

On the right side of the equation, each \( H_2O \) molecule contains 2 hydrogen atoms. Since there are 2 \( H_2O \) molecules produced, this means:

\[ 2 \times 2 = 4 \text{ hydrogen atoms} \]

Therefore, the total number of hydrogen atoms present after the reaction is also 4.