Carbon to carbon bond is nonpolar covalent since the difference of their electronegativity’s is 0. Carbon has an electronegativity of 2.5. 2.5 - 2.5 is 0 making the bond between those two atoms nonpolar covalent. I hope I answered your question.
B - Evolve into the closest species on the tree’s trunk
A0 = 1
a1 = 2
a2 = 1
a3 = 2
This can be solved by guessing and checking and making sure that all atoms on the left side are accounted for on the right side. Both sides must have the same amount of atoms or the balancing is not correct.
Two helium nuclei fuse to form beryllium nuclei which is highly unstable and spontaneously decays rapidly.
