What is meant by $Tin \ Plague$?

Explain the oxidation states of group $14$ elements.

Match the following:
| List-$I$ | List-$II$ |
| :--- | :--- |
| $A$. Carbon black | $I$. Electrodes in batteries |
| $B$. Graphite | $II$. Extraction of metals |
| $C$. Diamond | $III$. Abrasive |
| $D$. Activated charcoal | $IV$. Filler in automobile tyres |
| | $V$. Air conditioning system |

The order of catenation power is $Ge < Si < C$. What are the $C-C$,$Si-Si$,and $Ge-Ge$ bond energies (in $kJ/mol$) respectively?

Superphosphate is a mixture of

Select the member$(s)$ of group $14$ that $(i)$ forms the most acidic dioxide,$(ii)$ is commonly found in $+2$ oxidation state,$(iii)$ used as semiconductor.