How does a solid become a liquid ?
I get an example of an ice . When the molecules of the ice shake faster until it gets at 0 Celsius the molecules begin to separe or brake up from one to another .thei neighboring molecules can no longer hold them in place then the crystal structure begins to collaps and the ice become a swarm whit water floowing so here is geting in liquid state in this point is call melting point
Freezing
Is the revers of the example I have did before . As the liquid becomes to cool the particles go slow and get more closer by the time it pass.in this piont we can call him freezing point . As the time it pass the crystalline solid is bing forming .
When the liquid is becoming a solid the temperature is falling and the liquid becomes more viscous as its temperature decreases until it get in an brittle glass

Solids

Kinetic theory of matter

There are three states of mater solid ,liquid ,and gas and they behave quit differently from one another
Matter is anithing that takes up space and has mass
In other word all that you can touch smell or see is matter like your books
But light feelings and emotions are not matter

Atoms 

When two atoms combine form a particle that is call molecule 

They are the smallest particle that make up matter but there are differents types like an old atom make   Gold ring .

When two atoms of different types combine they can produce a new element like de hydrogen and the oxigen can creat water in H20

And some thing that I just say is that there are differents types of solids liquids and gases by the same way the “atoms”

Matter in motion 

In the objects when the particles get in contact they produce motion so the object move .

There is a theory call kinetic theory of matter that tells about the particles that are in constant random motion

Temperature y heat 

In the particles of materials the faster they go the higjher temperature they have and the same in the vice versa way 

An example is hot tea and iced tea 

They are the same particles but the difference is how much they move.

The temperature of a material is an inderect measure of the average kinetic energy of the particles that make up the material 

21.when a gymnast is jumping it produce kinetic energy  they half way up
It has potential energy when it is in the high point, when it is half way down it produce kinetic energy and when it is in the lower point before hitting the trampoline is potential energy
(Y  said about the air because it depends to the trampling he do )

Only answers:
16.becasue some people are soy ignorant in science so they have no wisdom in this subject
17.by using convection because both liquids change his temperature as time passes to the temperature of the room because they adapt or get the same temperature of the room
18.chemical energy: when water enter in their bodies they get energy’s to move
19.they are differents in the way of degrees because the three of then boil am freez at deferent temperature and they they are similar in they way that they are based of freezing and boiling points
20.i will do it for transfer the warm in this case my hand to cool in this case the cool water so it will get off from my arm so I will feel better

Exotermic:
Burning wood:because the fire that is produce by the wood is throwing off energy from the wood
Striking a match to light it:because the energy that is inside it is going out in the form of fire
Exploding dinamit:it give off energy when it react with oxygen to burn in a high temperature

In my opinion all this need oxygen to react ( something in common )

Endothermic reaction and exotermic reaction 

¿Why both ?

Because baking a bread has endothermic energy when it recept the heat and it do exotermic energy when it is expanding in mass 

I need to ocupaisse the third part of mi hous with colector area
In an example:1200=400
But I can't do that so there's an operation
Collector area
——————
Living space
So in this example is :
400
——
1200
So I need this for a good consume of energy in my house

Pendulum velocity 

Pendulum/long/times per minute 

1                  /5       /7

1                 /2.5    /10

1                /10      /5

Conclusion

The problem here is that if the pendulum is bigger it will go slowest 

And if is shorter it will go faster as we can see in the table using the 

Same pendulum but make him larger or shorter because it takes less

to do a swing when is shorter and vice versa 

Drawing of conclusion 

          |

          |                 =5 swings per Minut            

            |

            |

       O 

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            |                     = 7swings per minut

            

            |

       O                      

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            |                   = 10 swings per minut

       O