Physical and Chemical Properties and Changes

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Physical and Chemical Properties and Changes

• Integrated Science 1

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What is a pure substance?

• Matter made of only one kind of material with
  definite properties.
• Ex Elements (made of only one kind of atom) and
  Compounds (two or more elements chemically
  combined)

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What is a mixture?

• Physical combination of two or more substances in
  which each substance retains its properties.
• Ex Heterogeneous mixtures and Homogeneous
  mixtures

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Heterogeneous Mixtures

• Individual substances can be easily identified
• Do not appear the same throughout
• Can be separated by physical means
• Ex sand and salt, iron and gravel

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Homogeneous Mixtures

• All portions of the sample have the same
  composition
• Appear the same throughout
• Can be separated by physical means
• Ex solutions

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What is a solution?

• Homogeneous mixture of a solvent and a solute.
• SOLVENT causes solute to dissolve
• SOLUTE substance that is dissolved
• Ex Kool-Aid, iced tea, coffee

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Physical Properties

• Describe a substance and can be observed without
  changing the identity of the substance
• Ex density, texture, color, phase

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Phases of Matter

• Solid definite shape and volume
• Liquid definite volume but takes shape of
  container
• Gas expands to take shape and volume of
  container

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Physical Changes

• Alter the appearance of a material, but the same
  substance still remains
• Ex change in phase, color, texture, shape, size

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Phase Changes

• Melting solid to liquid
• Freezing liquid to solid
• Vaporization liquid to gas
• Condensation gas to liquid
• Sublimation solid to gas without becoming
  liquid
• Deposition gas to solid without becoming liquid

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Chemical Properties

• Explain how one substance reacts with others to
  form new substances
• Ex flammable, corrosive, volatile

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Chemical Changes

• Result in the formation of new substances with
  properties different than the original material
• Ex rusting, burning