Covalent Bonds Covalent bonds are formed when electrons are shared between two elements. The elements in covalent bonds are often close in electronegativity. This is because if one was much higher than the other it would steal an electron not share it. Neither takes electrons or loses any. Form molecules. Close electronegativity.
Ionic Bonds In ionic bonds are when metals take electrons fro nonmetals. When the electrons are stolen one becomes negative and one becomes positive so they are attracted towards each other. This forms a crystal structure because the negatives will always be surrounded on all sides by positives and not touch other negatives so they become a 3-d structure. The one that is taking is a higher electronegativity because it attracts the electrons from the other element with a lower pull. Very different electronegativity.
Compare and Contrast In order for the covalent bonds to form the electronegativities need to be different because that way the electrons can be shared not stolen and ionic need to take so the higher electronegativity allows that to happen. Covalent are nonmetal to nonmetal and ionic are metal to nonmetal because of electronegativities. Ionic has high melting and boiling points because bonds need to break but covalent are low because bonds don’t need to. Covalent are flexible o bond needs to break ionic are hard because bonds are strong.
Comparison Water Sodium Fluorine Water is covalent It is ionic because because both sodium has a low oxygen and electronegativity and hydrogen are fluorine has the nonmetals with close highest electronegativities. electronegativity of They don’t take the any element. electrons from each Fluorine takes other they share. electrons and one becomes positive and one negative so they are attracted to each other.