Why is deposition exothermic

Or frozen water solid to make ice. You've probably even seen frost on the grass in the winter. All of these changes in the phase of water are accompanied by either an input or output of heat , so they are either an endothermic reaction or an exothermic reaction.

The question then follows, what kind of change in energy accompanies each phase change? To understand this, think about the movement of the particles in each phase. You also need to think about how attracted the molecules are to each other within the phase. Solids contain particles that aren't moving so much as compared to a liquid or a gas. They have some thermal motion, but clearly not the same amount as a liquid or a gas.

Only after adding energy or heat do these particles start to move around faster. Think about a piece of ice. The molecules of water in the piece of ice are not moving much until the water starts to melt.

What allows the water to melt? Well, it's an addition of heat. What about when you boil water? You need to put the water over a flame in order to add heat to the system and have the water boil in order to make water vapor.

Feb 26, Because all of these slow molecular motion, i. Freezing has particles of a liquid slow down to form a lattice structure and become a solid phase. Condensation has particles of a gas slow down to form intermolecular forces and transition into a liquid phase. Deposition has particles of a gas slow down to form a lattice structure, becoming a solid and skipping the liquid phase.

Thus, the above three processes are exothermic with respect to the system. Related questions Why is burning wood exothermic?

I thought the wood is taking in heat to burn, therefore GOB Video Lessons. Microbiology Video Lessons. Calculus Video Lessons. Statistics Video Lessons. Microeconomics Video Lessons.

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