Metal Reactivity Series Order

Steps:

• Identify metals P, Q, R, S from the reactivity series (e.g., S as potassium, Q as magnesium, P as zinc, R as copper).
• Rank from highest to lowest reactivity based on displacement ability: more reactive metals displace less reactive ones from compounds.
• Compare options: S displaces Q, Q displaces P, P displaces R.
• Select order S > Q > P > R as it matches the series.

Why C is correct:

• C follows the standard reactivity series where S (most reactive) > Q > P > R (least reactive), per the electrochemical series law.

Why the others are wrong:

• A omits S and incorrectly places P above Q.
• B places P above Q, reversing their relative reactivity.
• D places R above Q, contradicting Q's higher reactivity.

Not enough information on exact metals, but assuming standard series, C fits.

Final answer: C