Chapter 4 Elements Compounds and Mixtures

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Chapter 4 Elements Compounds and Mixtures

• Section 1 Elements

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ELEMENT

• Definition An element is a pure substance that
  cannot be separated into simpler substances by
  physical or chemical means
• Grinding -heating
• Electrolysis -filtering

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PURE SUBSTANCE

• Definition of a pure substance A pure substance
  is a substance in which there is only one type of
  particle
• Because elements are pure substances, each
  element only contains one type of particle

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PURE SUBSTANCE

• The particles of a pure substance are alike no
  matter where the substance is found
• Example an iron skillet and a meteorite have
  the same type of particle (iron) in them

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ELEMENTS

• Have characteristic properties that do not depend
  on the amount of material that is present in the
  sample
• Elements are classified by their properties.
  They are grouped into categories according to
  their shared properties. If you know the
  category, you know the element.

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Elements are Grouped into 3 Categories

• Metals ( Copper)
• Nonmetals (neon)
• Metalloids (silicon)

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Properties of Metals

• Shiny
• Conduct electric current
• Conduct heat energy
• Examples tin,copper, iron, lead

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Properties of Nonmetals

• Dull
• Poor conductors of electricity
• Poor conductors of thermal energy
• Brittle
• Not malleable
• Example neon, iodine, sulfur

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Metalloids(Semi Conductors)

• Have properties of both metals and nonmetals
• Some shiny some dull
• Somewhat malleable and ductile
• Some conduct thermal energy and electric current
  well
• Example silicon, boron and antimony

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Characteristic Properties

• Physical such as melting point, boiling point,
  density, texture, color
• Chemical such as reactivity with acid or oxygen
  and flammability
• Electrolysis to separate water