Question

1. how do polar and nonpolar substances differ? give an example of each. (p. 3)

Explanation:

Polar substances have a dipole moment (unequal electron sharing, creating partial charges), like water ($\ce{H2O}$ where oxygen is more electronegative, leading to a bent shape and polarity). Nonpolar substances have symmetric electron distribution (no dipole moment), like methane ($\ce{CH4}$, tetrahedral and symmetric) or carbon dioxide ($\ce{CO2}$, linear and symmetric). Polarity affects solubility (polar dissolves polar, nonpolar dissolves nonpolar, "like dissolves like") and intermolecular forces (polar has dipole - dipole, hydrogen bonding; nonpolar has London dispersion forces).

Answer:

• Difference: Polar substances have a permanent dipole moment (due to unequal sharing of electrons, creating partial positive and negative charges), while nonpolar substances have a symmetric electron distribution and no permanent dipole moment.
• Examples: Polar - Water ($\ce{H2O}$); Nonpolar - Methane ($\ce{CH4}$)