Question 3.9: Polarity of A Covalent Bond Using the symbols δ- and δ+, ind...
Polarity of A Covalent Bond
Using the symbols δ- and δ+, indicate the polarity in each polar covalent bond.
(a) \text{C}-\text{O} (b) \text{N}-\text{H} (c) \text{C}-\text{Mg}
Strategy
The more electronegative atom of a covalent bond bears a partial negative charge, and the less electronegative atom bears a partial positive charge.
For (a), C and O are both in period 2 of the Periodic Table. Because O is farther to the right than C, it is more electronegative than C. For (c), Mg is a metal located to the far left in the Periodic Table and C is a nonmetal located to the right. All nonmetals, including H, have a greater electronegativity than do the metals in columns 1A and 2A. The electronegativity of each element is given below the symbol of the element.
(a) \overset{\delta +}{\underset{2.5}{\text{C}}} – \overset{\delta -}{\underset{3.5}{\text{O}}} (b) \overset{\delta -}{\underset{3.0}{\text{N}}} – \overset{\delta +}{\underset{2.1}{\text{H}}} (c) \overset{\delta -}{\underset{2.5}{\text{C}}} – \overset{\delta +}{\underset{1.2}{\text{Mg}}}
■ Quick Check 3.9
Using the symbols δ- and δ+, indicate the polarity in each polar covalent bond.
(a) \text{C}-\text{N} (b) \text{N}-\text{O} (c) \text{C}-\text{Cl}