1. Oxygen (O), Selenium (Se), and Tellurium (T e) commonly show a −2 oxidation state due to their high electronegativity.
2. Polonium (Po), being a metal, prefers to show positive oxidation states (+2, +4) and does not exhibit −2.
List I | List II | ||
---|---|---|---|
A | Robert May | I | Species-Area relationship |
B | Alexander von Humboldt | II | Long term ecosystem experiment using out door plots |
C | Paul Ehrlich | III | Global species diversity at about 7 million |
D | David Tilman | IV | Rivet popper hypothesis |
List I | List II | ||
---|---|---|---|
A | Mesozoic Era | I | Lower invertebrates |
B | Proterozoic Era | II | Fish & Amphibia |
C | Cenozoic Era | III | Birds & Reptiles |
D | Paleozoic Era | IV | Mammals |