Let’s Review Chapter 4

Videos Song about the Dudes of chemistry Lewis Dot http://www.youtube.com/watch?v=07yDiELe83Y&feature=related Lewis Dot http://www.youtube.com/watch?v=ulyopnxjAZ8

Vocab Dissociation (3) Spectroscope (4) Spectra (4) Energy (4) Ion (3) Ionization Energy (3) Nucleus (3) Proton (3) Electron (3) Alpha Particle (4) Physical Model (4) Conceptual Model (4) Inference (2) Evidence (2) Cathode Ray (4) Molecule (3) Compound (3) Quantum (4) Valence Electron (3)

Where are the following located? Transition Metals Halogens Noble Gases Groups 3-10 Alkali Metals Alkaline Earth Metals Group 1 Group 17 Group 2 Group 18

Structure of an Atom What are atoms made up of? Can you draw a Bohr Diagram of an element? Don’t forget to label the charges. What are the three types of bonds? How are they similar how are they different? Protons (+) in nucleus Neutrons (no charge) nucleus Electrons (-) outside nucleus in shells Ionic- taken not shared complete shell Covalent- shared equally complete shell Polar- unequal sharing complete shell

Trends in the Periodic Table What are three trends we discussed in the periodic table? What are families (groups) and periods? What can they tell you about trends. What group is the stable group? How do you know? Which group do you find the highest/lowest I.E and E.N? Left to right- IE. EN increase AR decrease Top to bottom- IE. EN decrease AR increase Groups/Family- columns Periods - rows Group 18 also known as Noble Gas, full valence shell Group 17 Highest IE and EN, Group 1 Lowest IE, EN

Important dudes discussed The following individuals contributed to the modern idea of the atom. How? Name the model, and what ideas they brought in. Democritus Dalton Thompson Rutherford Bohr Matter is made up of atoms Atoms are indivisible spheres Atoms contain negative charges called electrons, Model “Plum Pudding” Used Cathode Ray Tube Gold Foil Experiment showed: nucleus, and empty space. Model is called the Nuclear Model Used Spectra scope to add to the idea that electrons orbit in shells and each shell is an energy level PLANETARY MODEL

Spectroscope What is it what does it do? What do you see when looking at sun, incandescent, or a fire? What do you see if burning metal ions or when looking at a specific elemental tube? An instrument that separates light into its principal wavelengths A continuous spectra. All wavelengths are present in the light that is emitted That element’s specific spectral lines. Each element has its own “finger print” or lines specific to only that element. Elements emit light (photons) when decreasing in energy levels.

Rutherford Tell me about his experiment. What was his experiment? What did he do? What did it explain to him? How did his discoveries help our current level of understanding of the atom. What two things did he discover? He shot alpha particles through gold foil and observed the amount of deflection. It proved that there was a high concentration of positive charges in the middle (nucleus) and that the rest of the atom was consisting of mostly empty space. Our current model still uses the nucleus and we still believe that most of the atom consists of empty space Nucleus Empty space

Super Model – Study this well for the Test tomorrow! Ernest Rutherford – 1871- 1937 His famous experiment is known as the Gold Foil Experiment .

Super Model _ Study this well for the Test tomorrow! Ernest Rutherford– 1871- 1937 What he saw (evidence) What he concluded (Inference) Most of the alpha particles went straight through the foil (undeflected) The atom is mostly empty space Very few alpha particles bounced straight back (or at a large angle) The atom has a very small, very dense center (nucleus) Some alpha particles were deflected at a an angle. The nucleus must have a positive charge, since the positive alpha particles that came close to the nucleus were deflected at a small angle.

Bohr How is Bohr Model different from Rutherford? What evidence did he have to support his theories? How does a quantum relate to the light spectrum? Bohr believed that the electrons orbit the nucleus in different shells (energy levels) The spectral lines viewed through the spectra scope and comparing different wavelengths A quantum of energy is the amount of energy required to move an electron from one energy level to another

Physical and Conceptual Models Make a T-chart/Venn Diagram/ or Table Similarities and Differences Give an example of each Physical Model An object on a different scale Example: Model of airplane, schools. Conceptual model Describes a system, not a thing Example: using analogies to describe how photosynthesis works Similarities: Both help represent the concept or item trying to describe without using the idea or concept directly

Lewis Dot/Electron Dot Sulfur Carbon Phosphorus Boron Magnesium Argon