Composition of matter?

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Composition of matter?
Chapter 15 Section 1
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States of Matter
Solid - has a definite volume and a definite
shape (rock, baseball bat, salt crystal) Liquid
- has a definite volume but no definite shape it
flows and can be poured (tea, water)
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States of Matter (cont.)
Gas - has no definite shape or volume always
takes up all of the volume and shape of the
container (air, H2, O2) Plasma - no definite
volume or shape composed of electrically charged
particles usually with large amounts of energy
(flame, sun)
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Pure Substances

• Compounds
• Made of two or more different kinds of elements
  bonded together (water, baking soda)
• Can be broken down, but not by physical methods

• Elements
• Made of only one kind of atom (copper wire,
  charcoal)
• Cant be broken down further

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Mixture
A combination of two or more different kinds of
molecules. The key characteristic is that each
kind of molecule keeps its own identity. They
dont change when mixed. Examples air, waste
water Ways to separate filtering, boiling,
using magnets, dissolving
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Types of Mixtures

• Homogeneous
• a mixture that appears to be the same throughout
• particles are very small, not easily recognized
• mixture does not settle when allowed to stand
• also called a solution
• ex. stainless steel, air, coffee

• Heterogeneous
• a mixture that does not appear to be the same
  throughout.
• particles are large enough to be seen
• mixture can be separated (sometimes by just
  letting the mixture stand, settle)
• ex. concrete, oil and vinegar, sand in water

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How can you tell the difference between a
compound and a mixture? Mixtures can be
separated by physical methods, but compounds
cant.
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More on Mixtures!

• There are special types of mixtures that are
  called colloids.
• Colloids can have
• solids or liquids suspended in liquids (ex.
  milk)
• liquids suspended in gases (ex. fog)
• solids suspended gases (ex. smoke).
• The scattering of light by colloidal
• particles is called the Tyndall Effect.

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Suspensions

• Neither a solution nor colloid.
• A heterogeneous mixture containing a liquid in
  which visible particles settle.
• Example muddy pond water

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Question?

• What is the connection between red sunsets and
  suspensions?
• Write your answer on the top of your homework
  paper.
• Answer section review questions 1-5 on page 456.