• HYDROGEN + [non-metal "CENTRAL ELEMENT"] + OXYGEN 
• Gaseous and Aqueous forms have same name*
• When formed with Cl, Br, or I it follows this pattern:
• per   -ic acid  --from-->  per-   -ate anion
•       -ic acid  --from-->         -ate anion
•      -ous acid  --from-->         -ite anion
• hypo -ous acid  --from-->  hypo-  -ite anion
• When formed with other central elements, may not have as many forms.

• HYDROGEN + [ANION]
• In gaseous form, use rules for naming anions
• In aqueous form, add hydro-   -ic acid

E.g.

H₂S(g)  - hydrogen sulfide

H₂S(aq) - hydrosulfuric acid