Instructions:
1) Number each paragraph.
2) As we read each paragraph, highlight every word you do not know.
List them in the table below.
Guess a meaning for each word in the second column.
Word
Guess
Actual meaning
3) Summarise the paragraph in the box under it. Use dot points.
4) In the last box summarise the entire article in full sentences.
Temperature and the Particle Model
Using the particle model of matter, you would imagine small round spheres
very closely packed together in a regular pattern; they are gently vibrating in
their positions, yet they are not free to move around or change places with
each other. There are almost no spaces between them.
The amount of vibration of the particles represents the object's temperature. If
you add more energy by heating, the particles begin to vibrate harder. As they
vibrate harder, they have more frequent and more violent collisions with their
neighbouring particles. The more an object is heated the more the particles
vibrate and push apart and the more the object expands. If the object is cooled
the reverse happens. The particles vibrate less rapidly, they have less frequent
and less violent collisions with their neighbours, and the object contracts again.
The expansion and contraction of objects in hot and colder weather needs to
be considered when constructing footpaths and roads. Concrete footpaths
need to be poured in sections with 'expansion joints' made of soft,
compressible material between the sections to prevent them from cracking
when they expand during hot weather. On a bridge the roadway expands and
contracts as the temperature changes. Special joints made of metal are added
to bridges to allow them to expand and contract without affecting the driving
surface.
Different materials expand and contract at different rates. This presents special
problems for buildings and other man-made structures. When different
materials are used to construct something the expansion and contraction of
each material needs to be considered. Window frames generally expand at a
different rate to the glass of the window. Compressible materials are placed
between the frame and the glass to prevent the glass from breaking.
Final Summary of Article