There is no difference in electronegativity, so how do bonds form? Take for example C-C, they both want 4 electrons for a full valence shell to become more stable - they meet each other, but how come they share 4 electrons? There is no difference in electronegativity for them to attract each other. Also - can atoms only bond to themselves when they have half a valence shell full of electrons? E.g. carbon can bond to itself because it has 4 valence electrons but also needs 4 so another carbon fills its valence shell perfectly. Apologies if any parts of my question confuse you, I just started chemistry so I don't have a solid grasp on these concepts.