Chemistry

Chemistry

1. Focus 2

   • Acids, Bases and Neutrals
     • Acids
       • Any of a class of compounds that form hydrogen ions when dissolved in water, and whose aqueous solutions react with bases and certain metals to form salts. Acids turn blue litmus paper red and have a pH of less than 7. Their aqueous solutions have a sour taste
         • Lemons, oranges, vinegar, urine, sulfuric acid, hydrochloric acid
     • Bases
       • bases are substances that, in aqueous solution, are slippery to the touch, taste bitter, change the color of indicators (e.g., turn red litmus paper blue), react with acids to form salts, and promote certain chemical reactions
         • Soap, Ammonia, Drain Cleaner
   • Animal Testing
     • Reasons for testing cosmetic products on Animals

2. Focus 1

   • Definitions
     • Element
       • An element is a substance consisting of atoms which all have the same number of protons - i.e. the same atomic number.
     • Compound
       • A compound is a substance formed when two or more chemical elements are chemically bonded together.
     • Mixture
       • A mixture contains two or more substances that are not chemically combined.
     • Atoms
       • Proved by Einstein
       • The smallest chemical element that can exist
       • From the Greek word for 'indivisible'
     • Molecule
       • a group of atoms bonded together, representing the smallest fundamental unit of a chemical compound that can take part in a chemical reaction.
   • Naming Compounds
     • Elements are often named from their Latin names.
       • eg. Silver - Ag - Argentum
         • LATIN - SHINY GREY STUFF
     • Prefixes
       • With 2 non-metals together. Depending on how many of the first element there are is what the suffix will be
         • Mono-
           • 1
         • Di-
           • 2
         • Tri-
           • 3
         • If hydrogen is present, It is always written first
     • Metals and Non-Metals
       • Metals always come before Non-Metals
     • When there is a non-metal and a metal put together...
       • The compound will always end in 'ide'
   • Physical and Chemical Changes
     • Chemical Change
       • Synthesis Reaction
         • A reaction where two or more substances combine to form a more complex substance
           • A + B = AB
       • Decomposition Reaction
         • A reaction where one compound breaks down into two or more simpler substances
           • AB = A + B
     • Physical Changes
       • Physical changes-these are changes to matter which do not result in the formation of any new chemical. They are simply changes in the physical state (ie solid to liquid or gas or vice versa) or changes in form (eg breaking up a large rock into smaller pieces, dissolving a chemical in a solvent, or separating a mixture by physical methods such as evaporation)
   • Periodic Table
     • Classifying Elements
       • The number of PROTONS in an atom determines what element it is!
         • its atomic number!
         • Very hard to change the atomic number
       • Relative Atomic Mass
         • Protons + Neutrons averaged across all of the amount of that element across the Earth.
       • Mass Numbers
         • Total number of nucleons in the nucleus
     • Discovery
       • Dmitri Mendeleev
         • His mother believed in his potential and rode on horseback around Russia trying to find a university that would accept him
         • 1860's
         • He left spaces for elements which hadn't been discovered
     • Structure of the Periodic Table
       • Periods and Groups
         • The periods in the periodic table show the amount of electron shells an element has
           • There are 7 possible electron shells altogether in an atom
         • The groups on the periodic table tell us which group of metals/non-metals they are in.
           • There are 8 different groups
             • Alkali Metals
             • Alkaline earth metals
             • Lanthanides
             • Actinides
             • Transition Metals
             • Post-Transition Metals
             • Metalloids
             • Other Nonmetals
             • Halogens
             • Noble Gases
             • Unknown Properties
   • Structure of an Atom
     • Proton
       • Part of the Nucleus
       • Heavy / Positively Charged
     • Neutron
       • Heavy / No Charge
       • Part of the Nucleus
     • Electron
       • Same amount charge as Proton - Just Opposite
       • Nearly no mass at all - about 1800 times less than Proton or Neutron
       • Can jump from atom to atom whenever it's convienient
       • Electrons are wave particle dualities
       • Up to 7 shells of electrons
     • Nucleus
       • Nuclear component of the atom
       • Contains the protons and neutrons of the atom
       • Electrons are moving around the nucleus
     • Isotopes
       • Have different masses but the same chemical properties
       • belong in the same place on the periodic table

3. Skills

   • Naming Compounds
     • Same as in FOCUS 1
   • PH Scale
     • Range from 0-14
     • 0 - 6 = ACIDS
     • 6 - 8 = NEUTRALS
     • 8 - 14 = BASES
     • 7 = NEUTRAL

4. Focus 3

   • Corrosion and Combustion
     • Corrosion
       • CORROSION metal + oxygen = metal oxide
         • iron + corrosion = rust
     • Combustion
       • fuel + oxygen = oxides of elements in fuel
       • · Combustion is now accepted as a chemical reaction in which a substance (the fuel) reacts rapidly with oxygen. The products of the reaction are the oxides of the elements in the fuel.
   • Chemical Reactions
     • Endothermic Reaction
       • a chemical reaction accompanied by the absorption of heat
     • Exothermic Reaction
       • a chemical reaction accompanied by the evolution of heat
   • Reaction Rates
     • How fast a chemical reaction take place
       • I can measure how fast one reactant is used up, or I can measure how fast a new product is formed.
         • Factors affecting rate of a chemical reaction:
           • Stirring
           • Catalyst
           • Surface Area
           • Temperature
           • Concentration of Reactant
             • Concentration - a measure of how many solute particles are present in a fixed volume of solvent,
   • Law of Conservation of Mass
     • " The total mass of the reactants is always equal to the mass of the products when a reaction occurs in a closed system"