Answer:
10Rb° + 2RbNO₃ => 6Rb₂O + N₂
Explanation:
Given: Rb° + RbNO₃ => Rb₂O + N₂
=> 1st balance rubidium in RbNO₃ against Rb₂O by inserting a '2' coefficient before RbNO₃ and a '6' coefficient before Rb₂O
=> Rb° + 2RbNO₃ => 6Rb₂O + N₂ => Oxygen and Nitrogen are balanced. All that remains is balancing Rb by inserting a '10' coefficient.
=> 10Rb° + 2RbNO₃ => 6Rb₂O + N₂
Note: In balancing chemical equations, saving an element that is not part of a compound until last frequently gives balance by inspecting the number of elements of the specific kind and boosting its coefficient to balance the equation.
Balanced equation => 10Rb° + 2RbNO₃ => 6Rb₂O + N₂