how does a solid become liquid - freezing

There is a special temperature for every substance called melting point. when a solids reaches the temperature of its melting point, it becomes a liquid. for water, the temperature needs to be a little over 0°C for you to melt.; what is actually happening is the atoms in the ice become excited by the rise in temperature, atoms start moving around faster and push away from neighbouring atoms.  if their melting point were lower they also be liquids when the temperature is above 0°C. the reverse of the melting process is called freezing. freezing point, the temperature in which a liquid becomes solid. liquid water freezes and becomes solid ice when the molecules lose energy. at a liquid cools its particles slow down and come closer together.

Solids

Kinetic theory of matter

Kinetic theory explains the property of different states of matter. The particules in solid, liquid ang gases have different amounts of energy. They arranged differently and move in different ways. Matter is everything that takes up space and has mass. Anything that you can touch, smell or taste. Emotions are not matter.

Atoms

Atoms is the smallest particule that makes up matter. Atoms is make by the combination of 2 elements. When 2 atoms are combine they form a molecule.the physical states of matter depends on the atoms and molecules are moving. When the states are in solid particles are all together but when are in gases are completely separate .

Matter in motion

The particles in moving are kinetic energy. Particles move because of their collision with the other particles.

The temperature and heat 

The average of kinetic energy. When particles move fast it has a high temperature. Heat transfer of thermal energy from warmer to cooler objects

thinking critically

16. much discussion has focused on the need to drive more efficent cars and use less electricity.if the law of conservation of energy is true. why are people concerned about energy usage?
the problem is that the original form of the energy (gasoline) is  now mechanical energy and is of no use once wasteful.
to make it usable again it need to be gasoline which takes an extremely long process in nature.

17. if heat flows in only one direction, how can both hot and cold liquids reach room temperature as they sit on a table?
the heat from the hot object goes in the air and the air goes to the cold liquid

18. think about what happens to jack and jill in the nursery room. what kinds of enrgy are used? how was each energy form used?
if they are walking they are using kinetic energy but if they are sit down they are using potential energy

19. compare the 3 temperature scales you learned about. how are they different? how are they similar?
the celsius scale is based on 0°.
many physical and scientific formulas can be expressed on the kelvin scale
farenheit scale, water freezes at 32° and it boils at 212 °
similar: they are all based off the freezing and boiling points of water.
different: they define them at different numbers.

20. use what you know about the movement of thermal energy to explain why you would place a minor burn on your arm under cool, running water.
because heat is transfer from the warmer object to the cooler object.

DEVELOPING SKILLS

now when you are standing up on the tramp you have potential energy due to standing at a higher level  above ground.
when you are jumping on thr tramp you have both kinetic and potential energy. potential for the springs (as energy that is stored) and height.kinetic energy whwn you are moving in the air up and down.
so when you are in your highest point in the jump you have the most potential energy.
when in the middle half you have the most kinetic energy.
when you are back in the bottom, touching the mat you again have max potential energy due to the spings.

endothermic reactions                        exothermic reactions
baking bread                                                                         burning wood
                                                                                              striking a match to light it
                                                                                              exploding dynamite

why:                                                                                     Why:
is an endothermic reaction because it                                  because burning wood, striking a match to light
takes on the heat from its surroundings                               it and exploding dynamite gives off heat

skill builder

my house is 1500 square feet. we need a collector that occupies a third of the house.

collector area: 300ft2    1

living space:  1500ft2   3

pendulum skill builders

conclusion: among more shorter the rope the more times it is going to swings per minute

energy in the world

energy is the ability to work. all things in the wolrd have energy. also with need energy to move. energy can be stored or in movement. electrical energy is an example of a light bulb. the fire has heat energy. when you do force you are working with your muscular energy. sunglight is an example of solar energy. energy can move water, that is called hydel energy. windmills produce electricity , that electricity works by the wind and is called wind energy. we don´t see energy but energy is in all parts of the world. if you move , you are giving a force that is energy. streching a rubber band has potential energy, that is energy store