[Maximum number: 1]

Pairs of metals are connected together to make a simple cell, as shown.

The table shows the reading on the voltmeter when different metals are used.

If metal 2 is more reactive than metal 1 , the voltage measured is positive.
The greater the difference in reactivity of the metals, the larger the reading on the voltmeter.
What is the order of reactivity?

most
reactive

least
reactive

cerium

beryllium

cobalt

manganese

cerium

beryllium

manganese

cobalt

manganese

beryllium

cerium

cobalt

manganese

cerium

beryllium

[Maximum number: 1]

A sample of solid X was added to three different solutions to predict the position of X in the reactivity series.

\begin{aligned}
\mathrm{X}(\mathrm{~s})+\mathrm{FeSO}_{4}(\mathrm{aq}) & \rightarrow \text { no reaction } \\
\mathrm{X}(\mathrm{~s})+2 \mathrm{HCl}(\mathrm{aq}) & \rightarrow \mathrm{XCl}_{2}(\mathrm{aq})+\mathrm{H}_{2}(\mathrm{~g}) \\
\mathrm{X}(\mathrm{~s})+\mathrm{Zn}\left(\mathrm{NO}_{3}\right)_{2}(\mathrm{aq}) & \rightarrow \text { no reaction }
\end{aligned}

Which other solution would react with solid X ?

$\mathrm{CaSO}_{4}(\mathrm{aq})$

$\mathrm{CuSO}_{4}(\mathrm{aq})$

$\mathrm{MgSO}_{4}(\mathrm{aq})$

$\mathrm{Na}_{2} \mathrm{SO}_{4}(\mathrm{aq})$