Mixtures
A mixture is a combination of two or more substances.
Substances in a mixture can be separated.
This means that they are not chemically combined. Peas, carrots, and corn can be combined in a mixture.
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In fact, you can buy a bag of frozen mixed vegetables at the store. Each vegetable can be sorted into separate piles.
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The peas, carrots and corn taste the same whether they are separated or mixed together.
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All substances in a mixture that are separated out have the same properties as before they were mixed.
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Some substances can mix physically with other substances. The makeup of a mixture can vary. A mixture does not necessarily contain a specific amount of each substance.
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They are not joined together chemically, so each substance in the mixture keeps its own properties.
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You can separate the substances of a mixture, but you cannot change the properties of any of the individual substances.
Solutions
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In a solution, one or more substances are dissolved in another substance. The most common kind of solution is a solid dissolved in a liquid such as slat in water. In this kind of solution, the substance that is dissolved is the solute. In a solution of salt and water, the salt is the solute
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A solvent is the substance that takes in, or dissolves the other substance. Usually there is more solvent than solute. In salt water, the solvent is the water.
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Ocean water is a solution. But a solution does not have to be a liquid. The air you breathe, for example is a solution made up of gases. The steel used for buildings and cars is a solution. During the process of making steel, carbon and iron, two solids are melted into liquid form. The carbon is dissolved in the iron.
Solubility
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No matter what you do, you cannot make sand dissolve in water. The ability of one substance to dissolve in another is called its solubility. Solubility is a measure of the amount of a substance that will dissolve in another substance.
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Since sand does not dissolve in water, the solubility of sand in water is zero. Sometimes you can speed up the process of dissolving the solute by raising the temperature of the solvent. This is true for most solutes that are solids. For example, you can dissolve more sugar in warm water than you can in cold water.
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A change in the size, shape, or state of matter is an example of a physical change. A physical change does not change the particles that make up matter. The arrangement of the particles, however, may be moved around during a physical change.
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Breaking a pencil is a physical change. The pieces of the pencil are still made of wood and graphite. If you sharpen the broken ends, you can keep using the pencil. Another physical change is tearing. If you tear a sheet of paper into tiny pieces, it still is made of the same kind of matter.
Chemical Change
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If you leave an iron nail in a damp place, it will rust. Suppose you compare the rust with the iron nail. You will find that the nail and the rust have different properties. The color and harness of rust and iron are different. But is a different substance that results from a chemical change in the iron nail.
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Unlike a physical change, a chemical produces a completely different kind of matter. In a chemical change particles of one substance are changed in some way to form particles of a new substance with different properties.
INVESTIGATE How does matter change?
Please follow the instructions on your worksheet
C:\Documents and Settings\Edwin Del Cid\Escritorio\EVALUATION AND ASSESSMENT\EXERCISE 1.doc
INVESTIGATE How properties of glue?
can
you
change
the
Mixing glue with another substance can change its properties.
The properties of the new substance are different from the properties of the original substance.
C:\Documents and Settings\Edwin Del Cid\Escritorio\EVALUATION AND ASSESSMENT\EXERCISE 2.doc
INVESTIGATE How do substances mix?
Mixing candies properties?
C:\Documents and Settings\Edwin Del Cid\Escritorio\EVALUATION AND ASSESSMENT\EXERCISE 3.doc
with
nuts
can
change
its
Lets see how much information we were able to acquire from this lesson
ments and Settings\Edwin Del Cid\Escritorio\EVALUATION AND ASSESSMENT\LESSON SCIENCDE.docx
C:\Docu