Elements and Compounds

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Elements and Compounds
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Element

• A substance that cant be broken down into any
  other substances by chemical and physical means.
  There are a few more than 100 elements and they
  are listed in the periodic table of elements.

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Compound

• A substance made of two or more elements combined
  in a set ratio or proportion.
• Common compounds are H2O-Water, CO2-Carbon
  Dioxide, CO-Carbon Monoxide, NaCl-Sodium
  Chloride(Salt).

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Metals

• Most elements are metals and have luster(shine)
  because they reflect light.
• Most are solid at room temperature-except mercury
• Most have a high density and are good conductors
  of heat and electricity.
• Malleable-can be molded or hammered flat

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Non-Metals

• Have no luster
• Gaseous or solid at room temperature
• Have low densities and are poor conductors or
  heat and electricity
• Solid non-metals are brittle and break easily

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Metalloids

• Known as semimetals-they have properties of both
  metals and nonmetals
• Some have luster, some do not.
• Melting points and densities vary
• Considered semiconductors-they can conduct heat
  and electricity but not as well as metals.

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Minerals

• A naturally occurring inorganic(did not arise
  from a living thing) solid that has a crystal
  structure and a definite chemical
  composition-also known as a zeolite.
• Properties of minerals include-hardness, color,
  streak, luster and density.
• Halite is a mineral that you know as table salt.
• Coal is not a mineral because it was formed from
  once living things.

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How are minerals formed

• Minerals are formed when molten material cools
  and hardens inside Earth or on the surface.
• Other minerals form when materials dissolved in
  water come out of the solution most occur under
  ground in veins. Ex.-copper, silver and gold.