Question

A glass of water sitting in direct sunlight evaporates over time. Explain this phase change in terms of the types of heat transfer that occur.

Answer 1

For molecules of a liquid to evaporate, they must be located near the surface, be moving in the proper direction, and have sufficient kinetic energy to overcome liquid-phase intermolecular forces.Only a small proportion of the molecules meet these criteria, so the rate of evaporation is limited. Since the kinetic energy of a molecule is proportional to its temperature, evaporation proceeds more quickly at higher temperatures. As the faster-moving molecules escape, the remaining molecules have lower average kinetic energy, and the temperature of the liquid, thus, decreases. This phenomenon is also called evaporative cooling. This is why evaporating sweat cools the human body. Evaporation also tends to proceed more quickly with higher flow rates between the gaseous and liquid phase and in liquids with higher vapor pressure.

Answer 2

thank you so much. could you hep me with two more???

Answer 3

@NERD85176

Answer 4

yes

Answer 5

Well I can try to help you!

Answer 6

Describe how J.J. Thomson’s cathode–ray tube experiments led to his Plum Pudding model of the atom.

Answer 7

You could check out this website/pfd http://www.studyphysics.ca/2007/30/08_atomic/37_jjthomson.pdf

Answer 8

This vidio also covers the topic:
http://www.youtube.com/watch?v=2xKZRpAsWL8