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

8
8

4
4

2

Answer 1

In the chemical reaction 2H₂ + O₂ → 2H₂O, there are 4 atoms of hydrogen before the reaction (2 H₂ molecules, each containing 2 hydrogen atoms).

After the reaction, we still have 2 molecules of water (2H₂O), which each contain 2 hydrogen atoms, resulting in:

2 H₂O × 2 H = 4 hydrogen atoms.

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