The equations for several reactions involving metals Q, R and T are shown below. $\text{2QNO}_3(aq) + \text{Cu}(s) \rightarrow \text{2Q}(s) + \text{Cu(NO}_3)_2(aq)$ $\text{R}(s) + \text{TSO}_4(aq) \rightarrow \text{T}(s) + \text{RSO}_4(aq)$ $\text{T}(s) + \text{H}_2\text{SO}_4(aq) \rightarrow \text{TSO}_4(aq) + \text{H}_2(g)$ From these equations, what is the reactivity order of Q, R and T?