Chapter 2 Section 1 Notes

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Chapter 2 Section 1 Notes

• What is Matter?

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Chemistry

• Chemistry The study of matter and how it changes
• Examples of how we use chemistry everyday
• Cell phones
• soap
• food
• clothes

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Matter

• Matter anything that has mass and takes up space
• Examples of matter
• people
• rocks
• air

• The following are NOT matter because they have
  no mass dont take up space
• light
• sound
• electricity
• time

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Elements

• Elements substances that cannot be broken down
  into simpler substances
• Examples
• Helium
• Silver
• Neon

• If it is on the PERIODIC TABLE of the ELEMENTS,
  its an element!

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Elements are made up of atoms.

• Atoms smallest particle of an element that still
  has properties of an element
• Examples of substances made of atoms of the same
  element
• Diamonds made of carbon
• Foil made of aluminum

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Elements on the Periodic Table

• In 1760, there were only 16 known elements
  because scientists at the time werent clear of
  the nature of gases. Each element has its own
  symbol, made up on one or two letters. If there
  are 2 letters, the first one is ALWAYS capital
  and the second is ALWAYS lowercase. The current
  standard table contains 117 confirmed elements as
  of October 16, 2006. Each element behaves
  differently uniquely from each other.

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Examples

• Hydrogen H
• Carbon C
• Oxygen O
• Sodium Na
• Gold Au

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Compounds

• Compounds substances made of atoms of more than
  1 element joined together.
• Examples
• Sugar C12H22O11 Made of the elements carbon,
  hydrogen, and oxygen.
• Human Body contains oxygen, nitrogen, sulfur,
  phosphorus, hydrogen, etc. (Most of the elements
  exist as compounds instead of as free elements
  floating in the body.)

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Compounds

• Every compound is unique and different from the
  elements it is made from. Think of NaCl.

Picture of Chlorine gas
Picture of Sodium metal
Picture of table salt
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Molecules

• Molecules smallest unit of a compound that still
  behaves like the compound.
• Examples
• Water, H2O, is 1 molecule of water if you take
  away an atom of hydrogen or oxygen, it is no
  longer water.

• Oxygen, O2 molecules can also be made of atoms of
  the same element
• O2 is called a diatomic molecule

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Chemical Formula

• Chemical Formula the chemical symbols and
  numbers indicating the atoms contained in the
  basic unit of a substance.

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Subscripts

• Subscripts tells the number of atoms of each
  element in a compound.
• Examples
• H2O water, contains 2 hydrogen atoms and 1 oxygen
  atom
• CO2 carbon dioxide, contains 1 carbon atoms and 2
  oxygen atoms
• C3H8O rubbing alcohol, contains 3 carbon atoms, 8
  hydrogen atoms, and 1 oxygen atom.
• 3CO2 the number in front is called a coefficient
  and tells how many molecules there are of that
  compound.

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Pure Substances

• Pure substance any matter that has a fixed
  composition and definite properties
• There are 2 types of pure substances
• Elements
• Compounds

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Pure Substances

• Examples of pure substances
• Carbon element
• Methane, CH4 compound
• Silver element
• Neon element
• Carbon dioxide, CO2 compound
• Water, H2O - compound

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Mixtures

• Mixtures a combination of pure substances can
  be physically separated into parts
• Examples
• salad can separate lettuce, tomato, onion
• grape juice
• air we breathe 78 Nitrogen, 21 Oxygen (other
  1 carbon dioxide, argon, helium, and neon)

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There are 2 types of mixtures

• Homogeneous mixtures mixtures that are uniformly
  mixed
• Examples salt water, kool-aid, air we breathe
• We say that homogeneous mixtures are miscible,
  which means solids, liquids, or gases that can be
  mixed

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There are 2 types of mixtures (continued)

• Heterogeneous mixtures mixtures that are NOT
  uniformly mixed
• Examples flour and water, Italian dressing
• We say that heterogeneous mixtures are
  immiscible, which means they dont completely
  mix, can often see layers

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Graphic Organizer for Matter