AP BIOLOGY

Detailed explanation-1: -Smell of cake spreads through out the house while baking because of diffusion process in which the molecules move from a place where they are concentrated close together to a place where they are less concentrated and when molecules spread out evenly diffusion seems to stop.

Detailed explanation-2: -The smell of baking cake reaches us in the bedroom by the process of diffusion of gases released by the cake into the air. The rate of diffusion of hot gases into air is faster than that of cold gases into air.

Detailed explanation-3: -The correct answer is Diffusion. It is the movement of particles from an area of higher concentration to lower concentration.

Detailed explanation-4: -As the batter temperature rises, the gases in the air cells expand the stretchy gluten from the flour, then the chemical leavening agents release carbon dioxide. As the batter reaches 60C, water vapour begins to form and expand the air cells even further.