The reaction you provided, SO₂ + H₂O → H₂SO₂, is not balanced because the number of oxygen atoms on the left side of the equation does not equal the number of oxygen atoms on the right side.

Here's why:

* Left side: There are 3 oxygen atoms (1 in SO₂ and 2 in H₂O).

* Right side: There are 2 oxygen atoms (2 in H₂SO₂).

To balance this equation, we need to adjust the coefficients in front of the chemical formulas:

SO₂ + H₂O → H₂SO₃

Now, the equation is balanced:

* Left side: 3 oxygen atoms

* Right side: 3 oxygen atoms

The balanced equation reflects the actual reaction, where sulfur dioxide (SO₂) reacts with water (H₂O) to form sulfurous acid (H₂SO₃).