Find incorrect statement among the following

The correct option (incorrect statement) is: Covalency of carbon greater than 4 is possible

Let us analyze the statement step-by-step to understand why it is incorrect:

1. Electronic Configuration of Carbon:
Carbon has an atomic number of 6. Its ground-state electronic configuration is:
$1s^{2}2s^{2}2p^2$

2. Absence of d-Orbitals:
Carbon belongs to the second period of the periodic table, which means its valence shell is the second shell ($n=2$). The second shell contains only $s$ and $p$ subshells (specifically, one $2s$ orbital and three $2p$ orbitals). It lacks vacant $d$-orbitals because $d$-orbitals only exist for shells with $n\ge 3$.

3. Limit on Bond Formation:
Because carbon has only 4 valence orbitals available for bonding, it can share a maximum of 4 pairs of electrons. Without available $d$-orbitals, it cannot expand its valence shell to accommodate more than 8 electrons (octet rule). Therefore, the maximum covalency carbon can exhibit is 4.

4. Conclusion:
Since a covalency greater than 4 is impossible for carbon, the statement "Covalency of carbon greater than 4 is possible" is false, making it the incorrect statement.