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Matter
and atomic structure
Francine
Taylor-Campbell, Contributor
LET
US FIRST LOOK AT THE SYLLABUS REQUIREMENTS FOR THIS TOPIC Explain
the differences between the three states of matter in terms of energy and particle
arrangements. State
the evidence that supports the particulate nature of matter. Describe
the structure of atoms. POINTS
TO NOTE Matter
has mass and occupies space. The quantity of matter in a material is determined
by its mass. The
state that matter occupies depends on how the particles in it are packed. The
three states of matter are solid, liquid and gas. Matter
can be changed from one form to another by increasing or decreasing the kinetic
energy of the material. Processes
such as freezing, melting and boiling can change the form that matter takes. All
substances are made of atoms. These combine to form elements which later form
compounds. Students
must be able to describe the differences between the states of matter. Look
at the common example of ice, water and steam and apply the characteristics of
each state to them. By doing this, you will better understand the concepts. (See
table below) | Property
| Solid
| Liquid
| Gas | | Volume
| Fixed
volume | Fixed
volume | Volume
changes to fill space | | Shape
| Defined
shape | Takes
on the container's shape | Fills
entire container, no defined shape | | Particle
arrangement | Particles
are closely packed in a regular repeated structure | Particles
are arranged randomly with small spaces | Particles
are arranged randomly with large spaces | | Force
of attraction | Strong
attraction between particles | Moderate
attraction between particles | Weak
attraction between particles | | Energy
of particles | Particles
have little kinetic energy and only vibrate in fixed positions | Particles
have medium amounts of energy which allows them to move but not to separate from
each other | Particles
posssess large amounts of kinetic energy which causes them to move rapidly and
occupy any available space | | Expansion/
compression | Difficult
to expand or compress | Can
be expanded or compressed | Easy
to expand compress | | Representation
of particles | | | |
When
the temperature is increased, for example, with a piece of ice, particles gain
energy and will begin to move, changing the regular ordered structure. This represents
the process of melting and the ice will change to water. Further increase in temperature
will change the water to steam (gas) as the particles get more energy to move.
This is called boiling. To reverse this process, one decreases the temperature
by cooling (condensation) and freezing. These represent the way in which the states
of matter can be changed from one to form to the other. Sublimation describes
the change directly from solid to gas. Questions
1.
Show, using a diagram, how matter can be changed from one state to another (name
the processes involved). The
processes of diffusion and osmosis prove that matter is made up of particles.
If two
gases in separate jars are allowed to mix, then the gases will move from one jar
to the other until they mix completely. This is diffusion. When
particles move from one area to another through a semi-permeable membrane, example
in a solution where the solvent moves from a region of low to high concentration,
this is osmosis. 2.
Why is heat required to change a solid into a liquid? 3.
Explain why Baygon sprayed at the front of a room can be found at the back of
the room after a period of time? Francine
Taylor-Campbell is an independent contributor. | 
