Complete the following:
An acid is a substance that contains ______ H atoms.

Explanation

To complete the statement "An acid is a substance that contains ______ H atoms," we can follow these steps:

1. **Understanding Acids**: An acid is defined as a substance that can donate protons (H⁺ ions) when dissolved in a solution. This means that for a substance to be classified as an acid, it must have the capability to release H⁺ ions.

2. **Identifying H Atoms in Acids**: Acids can vary in the number of hydrogen atoms they contain. For example:
- Hydrochloric acid (HCl) contains one hydrogen atom and can donate one H⁺ ion.
- Sulfuric acid (H₂SO₄) contains two hydrogen atoms and can donate two H⁺ ions, making it a diprotic acid.

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