Answer:
Four electrons are involved in the interaction between the two carbon atoms of ethylene.
Step-by-step explanation:
Carbon belongs to Group 4 elements with atomic number 6. Hence, in neutral state it contains 6 electrons. Following are the electronic configurations of carbon;
Ground State : 1s², 2s², 2px¹, 2py¹, 2pz⁰
Excited State : 1s², 2s¹, 2px¹, 2py¹, 2pz¹
As shown in excited state configuration carbon have four unpaired electrons. In ethylene two out of four electrons of each carbon make two single covalent bonds with four hydrogen atoms and the remaining two electrons of each carbon make one single and one pi bond with neighbor carbon atom. Hence, four electrons of both carbons are involved in making two bonds with each other.