A little more information is needed. Rhenium is a transition metal, and as such, can have multiple valence states. If an ionic charge is known, for example, +2, then it can be assumed that the formula for the oxide would be RhO. If percent composition by mass is known, for example, 86.5% rhenium by mass, then math can be done to determine the formula of the oxide, which in this case, would also be RhO.
The chemical formula for cuprous arsenide is Cu3As.
The formula name for FeAs is iron(III) arsenide.
The formula for strontium arsenide is Sr3As2. It consists of three strontium atoms bonded to two arsenic atoms.
The chemical formula for stannous arsenide is Sn3As2.
Copper (III) doesn't exist; copper(II) arsenide is Cu3As2.
The chemical formula for cuprous arsenide is Cu3As.
The chemical formula for calcium arsenide is Ca3As2.
The chemical formula for sodium arsenide is Na3As.
The molecular formula for copper(I) arsenide is Cu3As.
The formula name for FeAs is iron(III) arsenide.
The formula for strontium arsenide is Sr3As2. It consists of three strontium atoms bonded to two arsenic atoms.
The chemical formula for stannous arsenide is Sn3As2.
Rubidium does not have a formula but a symbol: Rb.
Copper (III) doesn't exist; copper(II) arsenide is Cu3As2.
The chemical formula for rubidium phosphate is Rb3PO4.
The chemical formula for Rubidium Oxide is the formula: Rb2O.
The chemical formula for rubidium carbonate is Rb2CO3.