States of matter by dfhdhdhdhjr

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									I.P.S.I.A “ Zanussi” di Pordenone




                Le Science in pillole
                        O

                 Appunti di scienze




               A cura delle insegnanti
        Allida De Candido e Cristiana Ziraldo



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Subject Area: Science
Class Level and Course Title: first
Class / Science of Earth
Unit of Study: States of Matter



          States of matter



The students are introduced to a unit involving
States of Matter
Objective
•to known the three states of matter (solid,
liquid and gas);
•to list the general properties of each state;
•to describe them in terms of shape and
volume;
•to list everyday examples of each state;


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                   Forms of matter
    Matter is anything that takes up space and has weight
    Matter is anything that takes up space and has mass or weight.
    Matter exists in three forms or states - solid, liquid and gas.



Solids can be

soft                           or                     hard




Can you think of something on the Earth that is hard?
Rocks
Minerals

Liquids can be


                                      On the Earth


Gas can be



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                 Solid state
• Particles in a solid have fixed position.
•They are close together.
•If they are positioned in a regular structure they may
 form crystals.
•The forces holding them in position are strong, so solids
have their own shape.




•At 0 K (-273°C) the particles are stationary.
•At temperature above 0 K the particles vibrate but
 cannot move from their positions.
•As the temperature increases the vibrations become
  more energetic.




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             Liquid state
Liquids take the shape of the container into which
they are put.




Particles in a liquid are still fairly close together.
The forces between particles are not as strong as
in a solid and allow groups of particles to slide over
each other. This is why liquids can flow.
Particles in a liquid therefore do not have a fixed
position.
Liquids do not have a shape of their own.
They take the shape of the container into which
they are put.
These groups of particles move around slowly.




Because the liquid particles move around slowly the dye
gradually mixed with the water.

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                  Gas state
•The distances between gas are relatively large.
•Therefore they are almost completely free of forces
and so spread out and fill any container into which they
are placed.
•They are moving around at high speeds (approx. 500
m/sec at room temperature).
• Gases diffuse (spread out and mix) more quickly than
liquids.
•The directions in which they move have no pattern: they
are random motions (speed and direction).
•The gas particles inside this container are continually
 bouncing off the sides. It is these collisions with the
sides of the container that create the pressure inside
the container.




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What affects the pressure in a gas
There are several factors that will affects the size of
the pressure in a gas.
                            Mass
If the volume of the container is decreased, the particles
will have less distance to travel between collisions.
There will therefore be more collisions per second, i.e. the
pressure will increase.




      Volume                         Temperature
If more gas particles          If the temperature of a gas
are pushed into the            is increased its particles
container there will be        will move faster, there will
more            frequent       be more collisions each
collisions and so the          second and there will again
pressure will increase.        be an increase in pressure.




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                  To sum up
             Attributes of matter

   SOLID             LIQUID               GAS

Definite volume    Definite volume,   No definite
      and                  no         volume
     shape          definite shape     or shape




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        Changes of states

In the daily lives, there are a variety of
matter in the different states.




Objectives
To be able to classify and describe the
changes of state
To know haw matter changes and what
causes matter to change




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Changes          of      State        of       Matter
There are different changes that can take place.
Water, for example, can change from water to ice, which
is called freezing.
Freezing is what happens when a liquid changes to a solid.
                       Melting


                       Freezing




Water can change from ice to water, which is called
melting.
Melting is what happens when a solid changes to a liquid.


*




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Water can also change from a water to steam,
which is called evaporation.
Evaporation is what happens when a liquid changes
to                       a                      gas.
Water can change from steam back to water, which
is called condensation.
Condensation occurs when gas changes into a liquid.




                   evaporation
         Water                    Gas

                   condensation

There are some substances which can go from
being a solid, directly to the gas state, which is
called sublimation.
Solid carbon dioxide, commonly known as Dry Ice,
bypasses the liquid state altogether when it
changes to a gas.




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The last change of state is matter going from a gas,
directly to the solid state, which is called deposition.
Water vapours in the air during winter fall in the form of
snow,




                       Sublimation
               Solid                Gas

                       Deposition




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                    Cause of changes
                            Energy
Energy is either lost or gained during a change of state.

* When energy is applied to a solid, the tightly packed
particles of matter begin to move around, flowing over each
other. The result is the movement of liquid. The shape
becomes indefinite. The volume, however, does not change,
because the particles are still part of one another.

* When energy is applied to a liquid, the particles that make
up a liquid, begin to move about so rapidly, that they can no
longer hold themselves together. The result is the movement
of a gas. The shape is indefinite, and the volume becomes
indefinite.

•The reverse happens to gas when energy is taken away.
Water vapour, for example begins to liquefy as it cools.
Remember the cool mornings when fog is dense and close to
the ground? What happens? Dewdrops form. The water
vapours in the air cool to form liquid drops on grass.

* When energy is taken away from liquid, the particles in the
liquid slow down to low movement. The resulting solid, has
definite       shape      and        definite        volume.

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     To sum up
           Cooling


           Deposition?=bri
              namento

freezing                condensation


melting                    evaporation

             sublimation




              Heating




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                                    Test

1) When a solid changes into a liquid, it is called ......
     a)     vaporization
     b)     melting
     c)     evaporation

2) When a solid changes directly into a gas, it is called......
     a)     sublimation
     b)     evaporation

3) When a gas changes into a liquid, it is called ......
     a)     solidification
     b)     melting
     c)     condensation

4) Matter in a solid state has . . . . . volume and . . . . . .
   shape.
      a)     ____ no definite _____ no definite
      b)     ____ a definite ______ a definite
      c)     ____ a definite ______ no definite

5) The states of matter are the following:
   solids, liquids, gases, plastics.
       a)     True
       b)     False

6) States are also known as ?
      a)    phases
      b)    phrases
      c)    frases

7) Which phase of matter does not take the shape of
   the container it is in?
      a)    solid
      b)    liquid


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8) Liquids are hard to compress. Gases are easy to compress.
      a)    True
      b)    False

9) When solids reach their melting point they
    become ......
    a)   liquids
    b)   gases

10) What happens when a gas reaches condensation
    point?
     a)    it becomes a solid
     b)     it becomes a liquid

 11) What is evaporation?
     a)   When liquids turn into vapour
     b)   When solids turn into vapour

 12) What state / phase can fit into any container of any
   size and any shape?
     a)   a gas
     b)   solid
     c)   liquid and solid

 13) Gas and vapour means the same.
     a)   True
     b)   False

 14) Which state can hold their own shape?
     a)  a solid
     b)  a liquid
     c)  a gas

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15) Which state of matter resists very strongly if you
   try to change its shape?
      a)     gas
      b)     solid

16) When a liquid changes into a solid, it is called ......

       a)     melting
       b)     freezing
       c)     condensation

17) Solidification is when a gas changes into a solid.
      a)      true
      b)      false

18) Matter   in a ...... has a ...... volume and ...... shape.
      a)       gaseous state ___ no definite ___ no definite
      b)       liquid state _____ no definite ___ definite
      c)       solid state _____ no definite ___ no definite

19) When water freezes or when water becomes a vapour
    is it still the substance: water?
       a) yes
       b) no

20) Pick the correct statement:
    a)Solids become gases at their melting points
    b)Solids become liquids at their melting points




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