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?

(1 point)
Responses

5
5

2
2

8
8

4

Answer 1

In the chemical reaction \( 2H_2 + O_2 \rightarrow 2H_2O \), the coefficients indicate that there are 2 molecules of \( H_2 \) (each containing 2 hydrogen atoms) reacting with 1 molecule of \( O_2 \), producing 2 molecules of water (\( H_2O \)).

Calculating the number of hydrogen atoms:

- Before the reaction:
- \( 2H_2 \) has \( 2 \times 2 = 4 \) hydrogen atoms.

- After the reaction:
- \( 2H_2O \) has \( 2 \times 2 = 4 \) hydrogen atoms.

Thus, the total number of hydrogen atoms present after the reaction is still 4.

So, the correct answer is:
**4**