It's not accurate to talk about the "size" of a molecule in a single, definitive measurement. Instead, we talk about different dimensions:

* Bond Length: The distance between the hydrogen and sulfur atoms in hydrogen sulfide (H₂S) is about 1.34 Angstroms.

* Molecular Diameter: This is a bit more complex to define for a non-spherical molecule. You could look at the distance between the two hydrogen atoms, which is roughly 2.04 Angstroms, or the maximum distance between any two points on the molecule. However, these are just approximations.

* Van der Waals Radius: This refers to the effective radius of a molecule for non-bonded interactions. The van der Waals radius of sulfur is approximately 1.85 Angstroms.

Therefore, the size of a hydrogen sulfide molecule depends on which dimension you're interested in. It's roughly 1.34 Angstroms in terms of bond length, and around 2.04 Angstroms across.