How many pi bonds can the atom form?
Assuming the discussion is restricted to organic chemistry and we are talking about carbon, two pi bonds are possible.
Consider the triple bond in Ethyne
Carbon has four valence electrons so in order to make 4 bonds, it must hybridize its orbitals to make that possible. In this case, Carbon takes on an
The electrons in each carbon's
Carbon has the same
While a quadruple bond is possible for coordination compounds with transition metals, here is no hybridization scheme that allows for a quadruple bond to form between two atoms in organic chemistry.