Chemistry: Atoms, Elements, and Compounds

Chemistry: Atoms, Elements, and Compounds

1. The Atom (U7)

   • Atomic Theory
     • Important Discoveries
       • 4 Points About Atoms
         • Atoms of different elements have different properties.
         • All the atoms of an element are identical in properties such as size and mass
         • Atoms of different elements can combine in specific ways to form new substances
         • All matter is made up of smaller, indivisible particles called atoms.
       • J.J. Thompson
         • Used a cathode ray to test his theory that particles make up atoms
           • He tested this by causing non-radioactive particles to produce streams of negatively charged particles called electrons
         • Model of an Atom
       • Ernest Rutherford
         • Discovered that atoms had a nucleus at the centre of the atom
           • Model of an Atom
       • James Chadwick
         • Discovered that the nucleus contained neutral particles as well as positively charge ones, the neutral particles are called neutrons and the positive ones are called protons
       • Niels Bohr
         • Suggested that that electrons surrounded the nucleas in specific energy levels called shells.
           • He discovered that electrons jump between these shells by gaining or loosing energy
         • The Magnesium Atom
   • The Elements
     • Element Symbols
       • Common Element Symbols
         • Chlorine (Ca), Carbon (C), Calcium (Cr), Helium (He), Helium (He).
     • Element Classes
       • Definitons and Properties
         • Metals
           • malleable
           • Excellent electrical conductor
           • ductile
           • Gold, Sliver, Aluminium
         • Alloy
           • A mix of two or more metals
             • White Gold
         • Metalloids
           • Semi Conductor
           • Brittle
           • Pure Silicon
         • Non-Metals
           • reactive
           • brittle
           • Sulphur, Bromide
   • The Periodic Table
     • The atomic number represents the number of protons in an element (Eg. C is 6, O is 8, and Na is 11.)
     • Elements become positive ions by loosing electrons. K, Mg, and Al have ion charges of 1+, 2+, and 3+
     • Elements become negative ions by gaining electrons. The ion charges of P, S, Br are 3-, 2-, 1- respectively.
     • The atomic mass is the average mass of an element's atoms. The atomic masses of He, N, and Ca are 4.00, 14.01, and 40.8 respectivly.

2. Molecular Compounds (U9)

   • Molecular Compounds
     • Writing Formulas
       • Idenitify symbol of first element
       • Identify symbol of second element
       • Add subscripts
     • Naming Molecular Compounds
       • First element stays the same
       • 2nd element's suffix is changed to "ide"
       • Prefix added to the 2nd element
       • Prefix is added to the 1st element based on the number of atoms
         • di (2 atoms)
         • tetra (4 atoms)
         • mono (1 atom) Only used for second element
         • petra (5 atoms)
         • tri (3 atoms)
     • Molecular Compounds
       • Can be a solid, liquid, or gas at room temp.
       • Good insulator, poor conductor.
       • Relatively low boiling points.

3. Matter (U6)

   • Physical and Chemical Properites
     • Physical Properties
       • Viscosity
         • The resistance of a fluids flow
           • Syrup has a high viscosity
       • Ductility
         • Any solid that can be stretched into a long wire
           • Copper is a common ductile material
       • Conductivity
         • The ability of a substance to conduct heat. A substance with little to no conductivity is called an insulator
           • Most metals are good conductors, copper is a very good and commonly used conductor.
       • Colour and Lusture
         • The light a substance reflects gives it colour and lusture (shine)
           • The names of some substances (Eg. gold)
       • Hardness
         • A substances ability to resist being scratched
           • Mineral talc is softest (1), diamond is hardest (10).
       • Transparency
         • Allowing the transmission of light through a material
           • Glass is transparent
       • Density
         • An amount of mass in a given volume.
           • Water density is 1g/mL. Gold is 19g/mL.
       • Malleablilty
         • A substance that can be pounded into sheets.
           • Aluminum foil gold
     • Physical and Chemical Properties
       • Signs of a Chemical Change
         • A substance disappears
         • A colour change occurs
         • Production of light
         • A gas is evolved
         • Heat may be evolved or absorbed
         • A precipitate is evolved
   • About Matter
     • Changes in States of Matter
     • Principles of Matter
       • Particles present in matter are always in motion
       • All particles have spaces between them
       • All matter is composed of very tiny objects called particles
       • The particles in a substance attract each other
     • Matter
       • Mixtures
         • Hetrogeneous
           • Suspensions
           • Mechanical Mixtures
         • Homogeneous
           • Solutions
       • Pure Substances
         • Elements
         • Compounds
     • Definitions
       • Element
         • A substance that cannot be broken down
       • Homogenous
         • A substance dissolved into another creating a mixture where the parts are the same throughout
       • Pure Substance
         • Made up of only one kind of matter
       • Heterogeneous
         • A combination of pure substances where different parts are visible

4. Ionic Compounds (U8)

   • Ionic Compounds
     • Naming Ionic Compounds
       • The first element (metal) stays the same
       • The second element (non-metal) has irs ending change to "ide".
     • Ionic Compounds
       • Ionic compounds are pure substance consisting of at least one metal and one non-metal.
       • Form crystals, which are very regular arrangement of particles.
       • Have high melting points
       • Dissolve in water to form solutions that conduct electricity.
   • Atomic Theory Supports the Periodic Table
     • Bohr Diagrams
       • The amount of valence electrons can also be represented by another diagram called a Lewis Structure.
       • Lewis Structures
       • From the atomic number, we can see how many protons an element has. Also the number of protons and the number of electrons are the same in all atoms so that charges are balanced.
       • The outermost shell is called the valence shell. The electrons in the valence shell are called valence electrons.
       • The first shell can hold a maximum number of 2 electrons and each other shell after can hold a maximum number of 8 electrons
       • Bohr Diagrams
       • Protons and Neutrons are located in the nucleus, where electrons are located in energy shells surrounding the nucleus.
     • Forming an Ion Charge
       • Ions are formed from atoms that gain or lose electrons. Atoms become stable by having full shells so they do this by forming ions.

Images and files in the map