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? (1 point) Responses 4 4 8 8 2 2 5

Answer 1

In the chemical reaction \(2H_2 + O_2 \rightarrow 2H_2O\), the coefficients indicate how many molecules of each substance are involved.

• Before the reaction, there are \(2H_2\) molecules, and each \(H_2\) molecule contains 2 hydrogen atoms. So, the total number of hydrogen atoms before the reaction is:

  \(2 , \text{(H}_2\text{)} \times 2 , \text{(H atoms per molecule)} = 4 , \text{H atoms}\)

• After the reaction, the product is \(2H_2O\), and each water molecule (\(H_2O\)) contains 2 hydrogen atoms. Thus, the total number of hydrogen atoms after the reaction is:

  \(2 , \text{(H}_2O\text{)} \times 2 , \text{(H atoms per molecule)} = 4 , \text{H atoms}\)

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