Monday, April 11, 2016

Reinforced Concrete

Reinforced Concrete is used to build.

  • Concrete must be mixed a lot.
  • If you turn off the mixer, the concrete turns into the hard rock we all step on.
  • One of the tallest reinforced concrete buildings is the CN tower. (1815 ft or 553 meters)

Sunday, April 10, 2016

Separating Mixtures

There are four main ways on separating mixtures.
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One way is you can filter the mixture so that some particles cannot pass through.


Another way is that you can use floating.  For example, low density sawdust floats away from high density sand that goes to the bottom.
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Evaporation can be used to separate mixtures.  For example, you can have salt water.  Then you evaporate the water so you have salt left.

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The fourth way is to use magnetism.  Iron is attracted to a magnet and the nonmagnetic substance remains.

Solutions

A solvent is the substance that does the dissolving.
A solute is the substance that gets dissolved.
Solubility is the greatest amount of solute that a given amount of solvent can dissolve.

Mixtures

    A mixture is a physical combination of two or more substances that do not form a new substance.

There are different types of mixtures.

   A heterogeneous mixture is a mixture that its substances are big enough to see.  You can separate the pieces.  A good example of this would be trail mix.

homogeneous mixture is a mixture in which the particles are too small to see.  You can't see the individual parts. An example of this is milk.

Suspensions are mixtures which the particles settle and separate within a few hours.  An example of this would  be oil and vinegar as a salad dressing.  They can be shaken into a smooth-looking.  In minutes, the oil layers on top of the vinegar.

Solutions are particles in a mixture are the size of an atom of a molecule.  Solutions happen when one substance dissolves into the other. (ex. sugar and water)