CHEM B1110 Lecture Notes - Lecture 7: Lewis Structure, Nonmetal, Electronegativity
Document Summary
Chapters 8 & 9 chemical bonding and shapes of. Lewis dot structures are a convenient way to represent valence electrons. Dots don"t pair unless they absolutely have to so as long as there are 4 or less valence electrons there won"t be any pairs. Covalent bonds form between two nonmetal atoms that share electrons to complete their octets. To write lewis structures there are 4 steps: sum up valence electrons from all the atoms, the least electronegative atom goes in the center (normally the first atom in the formula) H always makes one bond; c always makes four bonds: draw bonds from the central atom to the others. Each bond represents two electrons: count the remaining electrons. Complete the octets on outer atoms first, then add the remaining electrons to the central atom. The greater the difference in electronegativity the more polar the bond. F is the most electronegative element and fr is the least electronegative.