A carbon atom is tetravalent, I.e. it can form four covalent bonds.
Which of the following bonds are possible between two carbon atoms?
Statement 1 and statement 2 are correct, but statement 2 is not the correct reason for statement 1.
Statement 1 and 2 are correct, and statement 2 is the correct reason for statement 1
Statement 1 is incorrect.
A covalent bond between two atoms is an overlap of their orbitals.
A carbon atom has four valence electrons in four orbitals. Let's say a bond is formed between two carbon atoms along X axis direction, another bond is formed along Y axis and the third bond is along the Z direction. So, it is not possible for the fourth orbitals to overlap as the three available directions are used in the formation of a triple bond. Hence, a quadruple bond is not possible between two carbon atoms.