Examples of polar and nonpolar covalent bonds using electronegativity.

📚 Quick Study Guide

• ⚛️ Electronegativity: A measure of an atom's ability to attract shared electrons in a chemical bond.
• 📊 Electronegativity Difference:
  • Nonpolar Covalent: Less than 0.4
  • Polar Covalent: Between 0.4 and 1.7
  • Ionic: Greater than 1.7
• 🤝 Covalent Bond: A chemical bond formed by the sharing of electrons between atoms.
• polar molecules and non-polar molecules.
• 💧 Polar Covalent Bond: Unequal sharing of electrons, resulting in a dipole moment ($μ$). Example: $H_2O$.
• 💨 Nonpolar Covalent Bond: Equal sharing of electrons. Example: $H_2$.
• 📏 Calculating Electronegativity Difference: Subtract the electronegativity values of the two bonded atoms.

🧪 Practice Quiz

1. Which of the following bonds is most likely to be nonpolar covalent, given the electronegativity values (Pauling scale):
   1. A) H (2.20) - Cl (3.16)
   2. B) Na (0.93) - Cl (3.16)
   3. C) O (3.44) - H (2.20)
   4. D) H (2.20) - H (2.20)
2. Which of the following molecules contains polar covalent bonds but is nonpolar overall?
   1. A) $H_2O$
   2. B) $NH_3$
   3. C) $CO_2$
   4. D) $HCl$
3. What range of electronegativity difference typically indicates a polar covalent bond?
   1. A) Less than 0.4
   2. B) Between 0.4 and 1.7
   3. C) Greater than 1.7
   4. D) Exactly 0
4. In a molecule of $HF$, which atom will have a partial negative charge ($\delta^-$)?
   1. A) H
   2. B) F
   3. C) Both H and F will have a $\delta^-$
   4. D) Neither H nor F will have a $\delta^-$
5. Which of the following bonds is the most polar?
   1. A) C-H (EN difference = 0.35)
   2. B) O-H (EN difference = 1.24)
   3. C) N-H (EN difference = 0.84)
   4. D) F-H (EN difference = 1.78)
6. Which of the following molecules is nonpolar, based on its structure and bond polarities?
   1. A) $CHCl_3$
   2. B) $BF_3$
   3. C) $H_2O$
   4. D) $NH_3$
7. Which of the following compounds contains only nonpolar covalent bonds?
   1. A) $NaCl$
   2. B) $CH_4$
   3. C) $HF$
   4. D) $H_2O$