The discoveries of Becquerel and the Curries were examined by video and discussed in terms of early radiation discoveries. Definitions of radioactive, and radioactive decay were listed along with examples. The radioactive particles were shown as alpha, beta, and gamma rays, along with the symbols for each and the penetrating power. The alpha decay of uranium into thorium was shown as an example, and the determination of the transmuted element's atomic mass and number was found.

Review the loss of energy and mass between the assembled nucleus and the nucleons. Relate the difference as mass deficit and binding energy determined by Einstein's formula. Discuss that nuclei are more stable as the atomic mass approaches 56 (iron) and that atoms below mass of 56 will naturally gain mass to approach 56. Atoms above 56 will naturally lose mass to approach 56. Examples of hydrogen to helium and uranium to thorium were used. The need for neutrons in a heavy nucleus to increase the strong force was discussed and keep the nucleus together.

Start with an explanation and definition of what a photon is. Explain what is meant by "Quantized", and that light energy comes in packets, or quanta, in whole numbers, with a quanta of light being a photon. A video showing Einstein's experiment dealing with the photoelectric effect, and how he used it to expand the theory of light as a particle was introduced for discussion. The photoelectric effect and Einstein's reasoning will be fully discussed in the next class.

Discuss how electromagnetic waves are formed from moving electric charges and how an electric field will generate a magnetic field which in turn will generate an electric field, and so on. The velocity of the EM waves are of only one speed, the speed of light, designated by the letter c. The formula for relating velocity, frequency and wavelength of WM waves was given and shown to be the same as the formula previously used when discussing light and sound. Since the velocity of EM waves is a constant, c, the formula can be rearranged to find the wavelength as c/f, showing that as the wavelength increases ( from gamma rays to radio waves) the frequency decreases.

Start with the statement "magnetism can produce electricity and electricity can produce magnetism". Describe how an electromagnetic wave is produced from a moving charge and a moving magnetic field. State Faraday's law and how it applies. Show how a generator produces a current from a rotating wire through a magnetic field, and how the current can be increased. Describe the difference between DC and AC current, and the "contest" in the late 1800's between Edison's DC and Tesla's (Westinghouse's) AC current to light up NY. Show why AC is more efficient, can transmit at higher voltage for longer distances, but required a step down transformer before entering the residence. Describe how the transformer works,both step up and step down types. Introduce electromagnetic waves, show sketched images of EM waves and describe how they propagate.

Discuss the effect that a magnetic field has on an electric charge, and on an electric current through a wire, in terms of deflection and direction. Depict the Earth as a large magnet, with a north and south pole. Explain that a compass needle which points toward the north pole is actually the south pole of the compass magnet. Describe how the Earth's magnetic field protects the planet from charged solar radiation.

Magnetic domain was used to explain how a substance can become a magnet. The domains were shown as magnetic fields produced by moving electric charges in the atoms. The production of a temporary magnet was discussed, as well as a permanent magnet. The action of an electric field creating a magnetic field around a wire was viewed, and seen as a series of concentric circles around the wire. Looping the wire was shown to increase the strength of the magnetic field within the loop and creating an electromagnet. Concentrating the magnetic fields into an iron bar inserted into the loops greatly increased the magnetic strength.

What holds the nucleons within the nucleus? Why don't 2 positively charged protons repel each other out of the nucleus? These questions are answered by indicating that there is a stronger force existing in the nucleus, stronger than gravity and stronger than the electromagnetic force between nucleons. This force is called the strong nuclear force. Discuss facts regarding the strong force and how it acts. Indicate that energy must be added to a nuclear system in the form of work in order to remove nucleons from the nucleus. Discuss that the energy of the assembled nucleus is less than the sum of the energy of each individual nucleon, and the difference is called the binding energy.

How a ferromagnetic substance is a magnet is outlined in a series of steps starting with a moving electric charge is surrounded by a magnetic field. A magnetic field is produced by the motions of an electric charge. The electric charge motion is produced by electrons rotating around the nucleus and spinning on their axis. Each produces a tiny electric field which produces a tiny magnetic field. Non magnetic substances have equal electrons spinning in opposite directions, their magnetic fields cancel out.
The theory of magnetic domains is introduced based on the magnetic field produced by spinning electrons.

Discussion of early investigations into the discovery and structure of the atomic nucleus, the description of the nucleus and the discovery of the proton and neutron. How the mass and charge of the nucleus is determined, the definition of atomic number, atomic mass, unit and mass number was discussed. We reviewed isotopes and their role in determining the decimal number of the average atomic mass.