AP BIOLOGY

Detailed explanation-1: -The differences in thermal properties between water and methane arise from differences in polarity between the molecules: Water is polar and can form intermolecular hydrogen bonds (due to high electronegativity of oxygen atom)

Detailed explanation-2: -The intermolecular bonds must be broken to form a gas. methane molecules are non-polar and do not have much attraction for one another. This is the reason why, at room temperature, methane is a gas while water is a liquid.

Detailed explanation-3: -Water and methane are both small molecules with atoms linked by single covalent bonds. However water molecules are polar and can form hydrogen bonds, whereas methane molecules are nonpolar and do not form hydrogen bonds.

Detailed explanation-4: -Water molecules are polar, with partial positive charges on the hydrogens, a partial negative charge on the oxygen, and a bent overall structure. This is because oxygen is more electronegative, meaning that it is better than hydrogen at attracting electrons. Water is an excellent solvent.

Detailed explanation-5: -U2) Hydrogen bonding and dipolarity explain the cohesive, adhesive, thermal and solvent properties of water. Ability of like molecules to stick together; water is strongly cohesive due to the many hydrogen bonds formed between them (tetrahedral arrangement).