Activity (reactivity) series and how each metal is extractedसक्रियता श्रेणी और धातु निष्कर्षण की विधि
NCERT Table 3.2, Fig 3.9 · interactive diagram
Parts and their functions
- K, Na, Ca, Mg, Al — most reactive (K, Na, Ca, Mg, Al — सबसे अधिक अभिक्रियाशील) — Never found free. Carbon cannot reduce their oxides (they hold oxygen more strongly), so they are got by electrolytic reduction of molten chlorides/oxide. Na⁺ + e⁻ → Na at cathode; 2Cl⁻ → Cl₂ + 2e⁻ at anode.
- Zn, Fe, Pb (and Cu) — middle of the series (Zn, Fe, Pb (और Cu) — श्रेणी के मध्य में) — Found as oxides, sulphides or carbonates. Sulphide → oxide by roasting (excess air); carbonate → oxide by calcination (limited air); then oxide reduced with carbon: ZnO + C → Zn + CO.
- Hydrogen [H] — the dividing line (हाइड्रोजन [H] — विभाजक रेखा) — Metals above hydrogen displace H₂ from dilute acids; Cu, Hg, Ag, Au (below H) do not.
- Mercury — heating alone (मर्करी — केवल गर्म करके) — Low in the series: 2HgS + 3O₂ → 2HgO + 2SO₂, then 2HgO → 2Hg + O₂ on heating. Copper from Cu₂S is also got by heating in air.
- Silver and gold — found native (सिल्वर और गोल्ड — मुक्त अवस्था में) — Least reactive: often found free in nature (also platinum, copper). Do not react with oxygen even at high temperature.
- Reactivity decreases downwards (नीचे की ओर अभिक्रियाशीलता घटती है) — A metal higher in the list displaces a metal lower in the list from its salt solution.
Original diagram drawn by Simple Learning Hub, based on NCERT Table 3.2, Fig 3.9. Report a mistake