Which describes the normal boiling point of a substance? A. The temperature at which the vapor pressure of a substance is greater than the air pressure at sea level.
B. The temperature at which the vapor pressure of a substance is less than the air pressure at sea level.
O C. The temperature at which the vapor pressure of a substance equals the air pressure at sea level.
D. The temperature at which the vapor pressure of a substance equals the air temperature at sea level.

Why do the strengths of london (dispersion) forces generally increase with increasing molecular size? choose one: a. heavier atoms have stronger attractions for each other than lighter atoms. b. dispersion forces are all equal in magnitude; there is no size dependence. c. dispersion forces arise from the attraction between the nuclei of atoms, and larger molecules have larger nuclei. d. dispersion forces arise from dipoles caused by the electron distribution being distorted. larger molecules have more electrons and, therefore, more distortions and a bigger force. e. dispersion forces depend on distance. larger molecules are farther apart and so the forces are smaller.