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Hello, we are going to continue with the unit about energy and matter.

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First of all, we are going to see how does energy change the matter.

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We will have two types of changes, the physical and the chemical one.

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So in the physical change...

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Hello, we are going to continue with the unit about energy and matter.

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So first of all, we are going to see how does energy change matter.

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We are going to have two types of changes, the physical one and the chemical one.

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In the physical change, we will use our energy to change the physical appearance of an object.

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For example, when we cut a piece of wood to make a land sculpture.

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In the chemical change, we will have some substance that mix together and with something like, for example, heat, will react.

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Both of them are changing their physical appearance.

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And here we have some examples. In the first video we have a person cutting the

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wood and in the second video we have some cupcakes that are growing because

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they have mixed some substance and with the heat they are reacting. In second

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place we're gonna see how does heat change matter and we are gonna

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distinguish between three types. First of all, the temperature variation is just

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the change of the temperature of the object. The change of the state is when

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the heat makes that object change its state, like for example when we have

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something solid and it becomes liquid. And expansion and contraction is also

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about the heat is for example, when we use the heat

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to make something bigger or smaller.

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Here we have also some examples in the temperature variation,

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we have an ice melting, now it's solid,

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but when it finished melt, it would be liquid.

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In the video about change of state,

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we have an ice putting into a cup,

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inside the cup, the water of the liquid is becoming solid.

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And in the expansion and contraction they have used heat, as you can see right now, to make the ball bigger or smaller and then they put it in the eye.