Answer : The balanced chemical reaction will be:
![6Rb+Au_2O_3\rightarrow 2Au+3Rb_2O](https://img.qammunity.org/2021/formulas/chemistry/middle-school/teudwqsuq4j3qama0f4iqssu0b8enaq31c.png)
Explanation :
As per question, when rubidium react with gold oxide then it gives rubidium oxide and gold.
This reaction is a single replacement reaction in which more reactive element displaces the least react element from its solution.
The balanced chemical reaction will be:
![6Rb+Au_2O_3\rightarrow 2Au+3Rb_2O](https://img.qammunity.org/2021/formulas/chemistry/middle-school/teudwqsuq4j3qama0f4iqssu0b8enaq31c.png)