How is a bond between Na and Cl different from a bond between C and O? What about a bond between N and N? Why are some bonds ionic and some covalent?

Question

anonymous · Answer

Whether a bond is covalent or ionic depends on the electronegativity difference between the participating atoms. Because that Na and Cl have very different electronegativities - Cl having a much higher electronegativity - the bond will be ionic - chlorine will fully take an electron from sodium. C and O will have a polar covalent bond (there is an electronegativity difference but not quite as large as the previous one). N and N will have a nonpolar covalent bond (no electronegativity difference). In covalent bonds atoms share electrons instead of giving and taking them.