Review the electron configuration of the inert gases. Review the maximum number of electrons which can be found in each of the energy levels, the last energy level in particular. Atoms which are classified as metals are defined and located, as well as those classified as non metals. The stability, the inert activity of the noble gases is due to the maximum electrons present in the last energy level of each atom, which is 8, except for helium which is 2. The group 1 atoms, lithium, sodium, and potassium are drawn with the electrons shown as numbers in each level, and as a dot in the last level. Each atom in this group has 1 electron in its last energy level. The concept of atomic charge neutrality was shown by subtracting the number of electrons from protons in each atom, arriving at a net charge of zero. Each group 1 atom was then sketched after "losing" the one electron in the outer level. The stability of each atom was based on its structure being now identical to one of the inert atoms. The number of electrons subtracted from protons at this point indicates an atom which exhibits a charge of +1. The atoms are now called Ions.

The electron configuration of the inert gases was determined for each. The meaning of inert was discussed, and related to the fact that these gases are referred to as noble gases. The Lewis formulas for each was drawn, and it was seen that the electrons in the last energy level of each of those elements was 8, the maximum number which can be held in the outermost energy level. The relationship between the maximum number of electrons in the last energy level and the inertness of the elements was elucidated. The reaction of sodium with water was seen on a video, to peak interest into chemical reactions which are coming.

An interactive computer site was used to allow Nicole to construct atoms with the proper number of electrons and their positions on the energy levels. When finished, we discussed then worked out a number of electron configurations utilizing a Lewis Dot formula.

Using the Bohr atom as the guide, the electron configuration for the first 11 atoms was drawn. The energy levels listed and the maximum numbers of electrons in each level was shown. Atomic numbers 12-18 were discussed, with atomic number 18 being drawn in one color and 19 in a second color, to differentiate. The increase in energy as the levels increased was stressed.

Review atomic number and atomic mass, the definitions and how to determine them. Show a diagram of the 3 types of hydrogen and elicit how each one differs atomically. Define them as isotopes and write a definition of isotope. Discuss how each element on the periodic table has a specific number of protons, but not neutrons.

The subatomic particles which comprise an atom were reviewed before moving on to atomic number and atomic mass. The atomic number was defined as the number of protons in the nucleus, and each proton was given a mass unit weight of 1 atomic mass unit. It was explained that this is not the actual mass, just a method to compare the masses. It was pointed out from the periodic table that each element contained a specific, individual number of protons, which was accorded its atomic number. If an atom contained a different number of protons, it was not the atom being discussed. The atomic mass was defined as the number of protons and neutrons in the nucleus of the atom. A neutron was afforded an atomic mass unit weight on 1 AMU, the same as a proton. That atoms of different elements may have the same number of protons and that this did not affect what it was, only the number of protons determine what an element is. The term isotope was introduced for discussion at the next class.

The super saturated solution prepared last week was looked at and a small crystal of solute added to the solution. The crystal formation in the liquid occurred at once, leaving a solid in the flask. A video also was used to show the crystallization, which was quite dramatic. Definitions of solute and solvent were used to explain the process. The colors emitted by hydrogen, neon and mercury, when excited by an electric current was demonstrated and the light being emitted by the electrons dropping to a lower energy level pointed out. The science behind this will be explained in detail in the next few lessons.

The definition of saturation was given, and examples shown to explain how a solution becomes saturated. The term supersaturated was introduced and explained. A lab investigation was undertaken to demonstrate supersaturation, and then to demonstrate how the dissolved substance in the supersaturated solution will be forced to "solidify out" by placing 1 small grain of the solid in the solution. While the solution was cooling, a demonstration of the attraction of a thin stream of water to a charged balloon was done.

Using diagrams, the physics of forced vibrations on a substance was defined as disturbances caused by an object emitting waves of a frequency which is the natural frequency of s second object. This causes the second object to vibrate at the same frequency. Some common examples were discussed. The physics of beats produced when two vibrating objects are held near each other was demonstrated using tuning forks of slightly different frequencies. The number of beats/sec was determined to be the difference in the frequencies of the tuning forks.

A classwork review sheet was filled out by Nicole which dealt with the early atomic structures. The most current theory, is that of the electron cloud model and was presented and compared to the Bohr atom from which it is derived. The sub atomic makeup of the atom was then presented with the presence of protons, neutrons and electrons. The charge of each was determined and based on the zero charge of the atom, the number of each present in a specific atom. The definitions were clearly written out along with the symbols used for each.