Matter is the Stuff around You

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Chemistry

• Matter is the Stuff around You

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Atoms are indivisible

• Atoms have three parts
• Protons are part of the nucleus and have a
  positive charge
• Neutrons are part of the nucleus and have no
  charge
• Electrons orbit around the nucleus and have a
  negative charge

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Electron Shells

• Electrons travel around the nucleus in orbital
  shells
• When an atom looses or gains an electron, it
  becomes an ion

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Periodic Table Organizes Elements
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Periodic Table Organizes Elements
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Periods

• All of the elements in a period (row) have the
  same number of atomic shells for their electrons

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Groups

• All of the elements in a group (column) have the
  same number of electrons in their outer shell
• These elements share similar characteristics

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Non-metals

• Non-metals are usually poor conductors of heat
  and electricity
• They are too brittle for shaping into wire or
  sheets
• Examples Carbon, Nitrogen, and Oxygen

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Metals

• Conduct electricity and heat well
• Can be molded and stretched into wire
• Form compounds easily
• Some are magnetic
• Some corrode and some shine

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Examples of Metals

• Aluminum Al
• Iron Fe
• Copper Cu
• Silver Ag
• Gold Au

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Alloys

• Mixtures of metals are called alloys
• Examples of alloys are
• Brass Copper Zinc
• Bronze Copper, Tin
• Steel Iron and Carbon

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Matter has physical and chemical properties
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Physical Properties - Solids

• Solids have molecules very close together and
  they vibrate in place
• Have a definite size and shape

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Liquids

• Liquids have molecules loosely spaced and they
  move more rapidly
• Have definite size
• Shape is same as container

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Gases

• Gases have molecules very far apart and they are
  very rapid
• They fill whatever container they are in
• No definite size and shape

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More Physical Properties

• Color (blue, red)
• Texture (rough, smooth)
• Hardness (hard, soft)
• Magnetic attraction (iron, nickel, cobalt)
• Specific gravity
• Melting point

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Chemical Properties

• Reaction with an acid (baking soda and vinegar)
• Reaction with oxygen (paper burns, nail rusts)
• Reaction with electricity (light from a
  fluorescent tube)

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Atoms Combine with other Atoms
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Elements

• Elements are substances made up of only one kind
  of atom
• Examples
• Helium He
• Oxygen O2

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Molecules

• Molecules are made up of two or more atoms
• The smallest part of a substance that keeps all
  the properties of that substance
• Sugar C6H12O6
• Water H2O
• Oxygen O2
• Carbon dioxide CO2

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Compounds

• Compounds are substances made up of two or more
  elements
• Each element loses its own physical and chemical
  properties
• NaCl (table salt) no longer has the properties of
  sodium or chlorine

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Mixtures

• Mixtures are substances made up of two or more
  elements or compounds
• Mixtures do not lose their physical or chemical
  properties
• Air is a mixture of Nitrogen, Oxygen, Argon, and
  rare gases
• Sand and water is a mixture
• All the elements in a mixture can be returned to
  their original state

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Solutions

• Solutions are mixtures of two or more substances
  where the molecules of one are spread out evenly
  between the molecules of the other
• Sugar water is a solution
• Salt in water is a solution

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Acids

• Acids, when in water, will release positively
  charged hydrogen ions (ions are electrically
  charged atoms)
• Lemon, vinegar, aspirin
• Sour taste (unsafe to do)
• Blue litmus paper turns red

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Bases

• Bases, when in water will release negatively
  charged hydroxide ions
• Draino, Ammonia
• Bitter taste (unsafe to do)
• Feels soapy or slippery
• Red litmus paper turns blue

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Salts

• Salts are formed when a base and an acid combine
• Hydrochloric acid (acid) Sodium Hydroxide
  (base) makes Sodium chloride (salt) and water

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Reactions

• There are chemical and physical reactions

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Chemical Reactions

• Chemical reactions cause a change in the chemical
  properties of matter. A new substance is formed
• Iron oxygen changes to iron oxide (rust on a
  nail)
• Silver sulfur changes to silver sulfide
  (tarnish on a spoon)

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Chemical Reaction Indicators

• Color change
• Precipitate forms
• Fizzing or bubbling
• A different odor is produced
• Heat or light is given off

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Physical Reactions

• Physical reactions change only the physical
  properties of matter. No new substance is formed
• Matter changes size or shape (wood to toothpick)
• Change in state (liquid evaporates to a gas)

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Conservation of Matter

• In a chemical reaction, matter is neither created
  nor destroyed
• Products look different from reactants
• Discovered by Lavoisier

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Photosynthesis

• Photosynthesis is the process by which plants
  change energy from the sun into sugar and water.
• Energy 6 CO2 6 H2O changed into C6H12O6
  6 O2

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Cellular respiration

• Cellular respiration is the process by which
  living organisms break down sugar into energy.
• C6H12O6 6O2 changed into 6 CO2 6 H2O