CHEMISTRY NOTES

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CHEMISTRY NOTES

• CHEMICAL REACTIONS
• EQUATIONS

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SIGNS OF CHEMICAL REACTION

• Change in temperature
• 1. ________________ releases energy in the form
  of heat. You can feel it getting hotter

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SIGNS OF CHEMICAL REACTION

• Change in temperature
• 2. _______________ absorbs heat energy from the
  reactants. It feels cooler than it did at the
  beginning

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SIGNS OF CHEMICAL REACTION

• Color change
• _______________ bubbles are seen forming or being
  released from the reaction

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SIGNS OF CHEMICAL REACTION

• Solid Production- a new, solid substance forms.
  If a solid is formed in a solution, the solid is
  called a ___________________

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SIGNS OF CHEMICAL REACTION

• A CHEMICAL REACTION HAS OCCURRED IF THE
  __________________________ OF THE REACTION ARE
  DIFFERENT FROM THE __________________________ OF
  THE REACTION

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RULES OF CHEMICAL RXNS

• Starting chemicals, elements or substances are
  called ___________________, because they are
  going to react to form something new.

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RULES OF CHEMICAL RXNS

• Ending chemicals, elements or substances are
  called ___________________, because they were
  produced in the reaction.

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RULES OF CHEMICAL RXNS

• All the __________ found at the start of a
  reaction must be present at the end of a reaction.

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RULES OF CHEMICAL RXNS

• This is the Law of _________________________
• All matter (measured as mass) in the _________
  must be present in the ____________.

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CHEMICAL BONDS

• A chemical bond occurs between _______________.
• Bonds only involve _________________________

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CHEMICAL BONDS

• Electrons can be transferred between atoms
• Called an _________ Bond
• Example

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CHEMICAL BONDS

• Electrons can be shared between atoms
• Called a __________ Bond
• Example

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CHEMICAL FORMULAS

• A shorter, easier way of showing chemical
  reactions using symbols instead of words
• ________________ shows the ratio of elements in
  a compound

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CHEMICAL FORMULAS

• Subscript numbers behind a symbol tell how many
  atoms of that element there are in the substance.

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CHEMICAL FORMULAS

• Example Hydrogen Peroxides name means 1
  Hydrogen for every 1 Oxygen.
• The formula is H2O2

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CHEMICAL FORMULAS

• What does Carbon Dioxide mean?
• What is its formula?

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CHEMICAL FORMULAS

• What are other examples of formulas you can think
  of?

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BALANCING EQUATIONS

• 1. Write the reaction in words.
• 2. Write the chemical equation.

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BALANCING EQUATIONS

• 3. Count all of the atoms for each element on
  each side of the equation.

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BALANCING EQUATIONS

• 4. Choose ___________ to place in front of each
  molecule to make each side of the equation
  balance.

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Classifying Chemical Reactions

• Synthesis
• Decomposition
• Single Replacement
• Double Replacement

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Synthesis

• Two or more elements combine to form a more
  complex compound
• A B ? AB
• Hand kerchief ? handkerchief
• Example C Cl2 ? CCl4

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Decomposition

• Breaks down compounds into simpler substances
• AB ? A B
• Schoolbook ? school book
• Example Al2O3 ? Al O2

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Replacement

• A reaction in which one element replaces another
  in a compound, or two elements in different
  compounds trade places
• AB C ? AC B (Single)
• AB CD ? AC BD (Double)