martes, 30 de abril de 2013

Particles in montion







Matter is made of atoms and this atoms are in a costant motion. This is the basis for the "Kinetic theory of matter". Matter can be divided in: solid, liquid and gases.


SOLID: 
  -Has definate volume and shape
  -Particles are close and don´t move
  -Particles together form a regular pattern
  ~The particles vibrate, but they can not move from one part of the
    solid to another part
  ~Solid can not easily change in shpe or volume
         When it change is by breaking it




LIQUID: 
  -Define volume, but not shape
  -More kinetic energy than solid
  -Particules are attracted to one
  -Particles in a liquid are not fixed
  -Particles can move from one plance 
   to another
  ~Particles are close toghether, 
     aren´t tightly
  ~Attached to one another
  ~Particles can slide past another




GASES:
  -Not have definate volume or shape
  -Most kinetic energy
  -Particles are not close
  -Particles can move easoly in any direction
  -Space between particles can decrease or increase
  ~Particles are very far part
  ~The space between the particles can change more
     easily

lunes, 29 de abril de 2013

Pure Subtances and mixtures



  How can matter be classified?


Matter is anything that has mass and  takes up space. Matter it made up of building blocks  called atoms.The matter can be divided in:



 -Pure substance: 
Pure substance is  a substance that has define physical and chemical properties such as appearance ,metling point and reactivity. Pure substance  are made up of one type of particle.

Compounds are also pure substances. Two different kinds of atoms make up each chemically combinaded particle, or molecule.
Physical change such as melting, freezing, cutting or smashing do not change the indentity of pure substance. The chemical bonds that hold atoms together can not be broken easily.When a pure substance undergoes a chemical change, it is no longer that the same substances.
Elements is made  one or more of the same kind of atom chemically compund.




 -Mixtures:
A mixture is a combination of two or more substances that are combined pshysically. Unlike elements and compunds, mixtures are not pure substances- Mixtures contain more than one substance. Also mixtures don't have defined chemical makeup.
Mixtures can be separated by pyshical changes,because the mixtures don't lose the identity of the substance. But not all mixtures are easy to separate, because of that we have: Heterogeneus and Homegeneus mixtures.


~Heterogeneus mixture: is one that does not have a uniform  composition. 

      -Suspensions: are mixed in which the particles of a material are spread thoughount a liquid or gas but are   
                            too large to stay mixed without beign stirred or shaken.
      -Colloids: particles are spread throught a liquid or gas.
      -Solutions: one substance is dissolved in another