Notes of lessons on the Herbartian method (based on Herbart's plan) . .Application of heat drives molecules apart. II. Presentation. 1. Definition of Process.—General name for change fromliquid to gas is— Vaporisation, but (Vaporisation at 2120 F. = boiling, orwe distinguish^, ebullition, and between ^Vaporisation below 2120 = evaporation. Therefore Evaporation is the turning of water intovapour or gas at any temperature up to 212°. It differsfrom ebullition, for there are no bubbles seen and no noiseheard. 2. Some Conditions which affect its rapidity : — (a) Temperature of Air. The hotter the
Notes of lessons on the Herbartian method (based on Herbart's plan) . .Application of heat drives molecules apart. II. Presentation. 1. Definition of Process.—General name for change fromliquid to gas is— Vaporisation, but (Vaporisation at 2120 F. = boiling, orwe distinguish^, ebullition, and between ^Vaporisation below 2120 = evaporation. Therefore Evaporation is the turning of water intovapour or gas at any temperature up to 212°. It differsfrom ebullition, for there are no bubbles seen and no noiseheard. 2. Some Conditions which affect its rapidity : — (a) Temperature of Air. The hotter the air the greater its capacity for receiving moisture, alsothe greater the rapidity of the process. (b) Rapidity with which air in neighbourhood isrenewed—for air can become saturated like asponge. (c) Extent of Surface exposed also affects the rate ofthe evaporation, for the vapour is only derivedfrom the surface, and this is one of the greatestdifferences between evaporation and ebullition. 182 Notes on Herbartian Method III. Association. As in
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