Question 1 • Physical Science
To balance a chemical equation, count each kind of atom separately and adjust the coefficients until every element has the same number of atoms on both sides. For this equation, the balanced form is 2Na + 2H₂O → 2NaOH + H₂, with two sodium, four hydrogen, and two oxygen atoms on each side. The total number of atoms does not have to stay the same, so choice C is not the right rule.
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