In which sample are the particles arranged in a regular geometric pattern? 1.) HCI (L)
2.) NaCl (aq)
3.) H2 (g)
4.) I2 (s)

4) I2 (s)

Explanation:

Only solids can create regular geometric patterns (crystal structures). NaCl doesn't count in this case because it's dissolved and are in the form of ions.

I₂ (s) is a solid so it can have a regular geometric pattern in it, the molecules will be closely spaced with no translation motion. It will have a fix volume and fix shape.