In the activity series, any metal on the list can be oxidized by the ions of elementsit. The solution contains H+(aq). This solution will oxidize and thus dissolve Zn(s) and , which appear above H2(g) on the list. Platinum, is distinguished by its lack of reaction with
nickel nitrate
nitric acid
above
sodium nitrate
Pt(s)
below
Pb(s)
Zn(s)

Below

Nitric acid

Lead

Sodium nitrate

Explanation:

The activity series is an arrangement of metals in order of decreasing reactivity. Metals that are higher up in the series displace metals that are lower in the series from dilute solutions. Hence, when the ion of a metal that is lower in the series reacts with a metal that is higher up in the series, the latter is oxidized.

Dilute acids dissolve metals above hydrogen in the activity series such as as zinc and lead. Platinum is much lower than sodium in the activity series hence platinum does not react with sodium nitrate.

they it depends on if one believes about radioactivity, they make a geiger counter beep but maybe it was going to beep anyway electronics do wierd things all the time or it was programmed to beep near certain metals.