Use the chemical reaction to answer the question

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)

8

5

4

2

Answer 1

In the chemical reaction \( 2H_2 + O_2 \rightarrow 2H_2O \), there are 4 hydrogen (H) atoms present before the reaction (from 2 molecules of \( H_2 \), since each \( H_2 \) molecule has 2 hydrogen atoms).

After the reaction, the products are 2 molecules of water (\( 2H_2O \)). Each water molecule contains 2 hydrogen atoms, so:

\[ 2H_2O \text{ has } 2 \times 2 = 4 \text{ hydrogen atoms.} \]

Therefore, there are 4 hydrogen atoms present after the reaction.

The answer is 4.