The Atom and its Nucleus
1. Rutherford Experiment: It was quite the most incredible event that has ever happened to me in my life. It was almost as incredible as if you fired a 15-inch shell at a piece of tissue paper and it came back and hit you. On consideration, I realized that this scattering backward must be the result of a single collision, and when I made calculations I saw that it was impossible to get anything of that order of magnitude unless you took a system in which the greater part of the mass of the atom was concentrated in a minute nucleus. It was then that I had the idea of an atom with a minute massive center, carrying a charge. —Ernest Rutherford
2. Rutherford Model of an atom and limitations.
4. Nucleons ... a proton or a neutron.
Nuclide – a particular type of nucleus with a certain number of protons and neutrons.
5. Z is the atomic number and it represents the number of protons in the nucleus. Also represents the electric charge in units e.
6. A is the mass number and represents the total number of nucleons.
7. N = A - Z and provides the number of neutrons
8. Isotopes. Nuclei with the same number of protons and electrons but different number of neutrons. It is the same chemical but has different physical properties.
9. Strong Nuclear Force. Attractive force that binds the nucleons together. At a short range it is much larger than the electrical force. Yet for larger separations the force is nearly negligible.
10. Nuclear radius. R = 1.2 x A1/3 x 10-15m. A is the mass number and this result tells us that the nuclear density is the same for all nuclei.
Helpful LINK. The ABC's of Nuclear Structure
HW. PG 372: 3-9, 11.
LINK. Why atoms don't collapse
E = hf = hc/wavelength