Energy and states of matter

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Energy and states of matter : 

Energy and states of matter

The four states of matter : 

The four states of matter There are four states of matter. We will only investigate 3 in any detail: Solids Liquids Gases You should be familiar with this

Physical changes : 

Physical changes A physical change is a change in which no new substances are formed and most physical changes are reversible. Examples: changes of shape, changes of states, passing electricity through a copper wire. I just took this from Wikipedia. It’s hyper-linked on my wikispace

Phase changes : 

Phase changes There are 6 that I expect you to know. Page 348 has a good diagram.

Endothermic vs. exothermic : 

Endothermic vs. exothermic Any phase change that requires energy to proceed is endothermic Examples are: boiling, melting, and sublimation. Take melting. What has more energy, a solid or a liquid? Therefore changing from a solid to a liquid requires energy. Hence, it’s endothermic.

Endothermic vs. exothermic : 

Endothermic vs. exothermic Any phase change that releases energy as it proceeds is exothermic Examples are: freezing, condensation, and deposition. Take freezing. What has more energy, a solid or a liquid? Therefore changing from a liquid to a solid releases energy. Hence, it’s exothermic.

Energy : 

Energy Understanding how energy flows from one substance to another is an important part of the study of chemistry. There are two units of energy that we will be studying in this course. The joule (more common) The calorie

The joule : 

The joule One joule is defined as the amount of energy required to raise one gram of water one degree Celsius. Sample problem: If 400. J of energy are transmitted to a 50ml sample of water, what will the change in temperature be? Assume the density of water is 1 g/ml.

Solution : 

Solution One J will raise 1 gram of water 1 degree. Set up the problem Write the givens Write what you’re looking for Come up with a plan Solve the problem

Classifying matter : 

Classifying matter You will need to do this on your own. Look it up on the wikispace That’s it