Explanation:

The size of a hydrogen atom is typically measured in the scale of angstroms or meters:

- Option 1: 10^–10 m - This is equivalent to 1 angstrom (Å), which is the approximate size of a hydrogen atom. Correct Answer

- Option 2: 10 µm - Micrometers are far too large; atoms are much smaller than this scale.

- Option 3: 10 mm - Millimeters are significantly larger than the atomic scale.

- Option 4: 1000 Å - This is equivalent to 100 nm or 10^–7 m, again far larger than an atom.