Chapter 3.2 The Structure of the Atom Discovery of the Electron The first discovery of a subatomic particle resulted from investigations into the relationship between electricity and matter. In the late 1800s, many experiments were performed in
which electric current was passed through various gases at low pressures. These experiment were carried into glass tube knowns as cathoderay tubes. Cathode ray and Electrons Observation: investigators notice that when current was passed through a cathode-ray tube, the surface of the tube directly opposite the cathode glowed. Hypothesis: they hypothesized that the glow was caused by a stream
of particle which they called a cathode ray. The ray travel from the cathode to the anode when current pass through the tube. Experiment : carried out by Joseph John Thompson (English physicist) in 1897 Joseph John Thompson was curious about the composition of the cathode ray :wanted to know what the cathode ray were, where they came from , and if they had any mass or charge.
Cathode ray tube Cathode Ray tube Experiment Plum Pudding Model Conclusion: Because atoms are electrically neutral, they must contain a positive charge to
balance the negative electrons Because electrons have so much less mass than atoms, atoms must contain other particles that account for most of their masses. Thompson then proposed the Plum Pudding model. Discovery of the Atomic
Nucleus Thompson model was disproved in 1911 by Earnest Rutherford and his associates Hans Geiger and Earnest Marsden. The scientist bombarded a piece of gold with alpha particles (positively charged particles with about 4 times the mass of a hydrogen atom)
They expected alpha particles to pass through with only a slight deflection. Discovery of the Atomic Nucleus Rutherford concluded that the force must be caused by a very densely packed bundle of matter with positive electric charge. Rutherford called this positive bundle of matter the
nucleus. He also discovered that the volume of a nucleus was very small compared with the total volume of an atom. (if the nucleus was the size of a marble than an atom would be the size of a football field) Composition of the Atomic Nucleus Scientist then concluded that all atomic nuclei are made up of two kinds
of particles :Protons and neutrons. (with the exceptions of hydrogen atom) Proton (+) Electron (-) Neutrons (neutral) The atom Forces in the nucleus: Generally, particles that have the same
charge repel one another. When two protons are extremely close to each other , there is a strong attraction between them. (same attraction for neutrons) The forces that holds the nuclear particles together (p-p, n-n, & p-n) are referred to as nuclear forces.
Because the radii are so small they are expressed in picometer (1pm= 1x10^-12 m ) 0.000000000001m Classwork pg76 #1-5
A self- in- relation model. People grow toward relationship. People grow toward mutuality. Growth happens through relationship. Connection is needed to develop future orientation. Mutual empathy especially as modeled in therapy can model respect for culture. Through relationship each person...
Therefore, it is difficult to compare directly the HRV of a subject during standing meditation and during sitting meditation. On the other hand, we did find that for those subjects who were in the sitting position throughout the experiment, their...
Eat Smart When You Eat Out Eating out:-is related to increased weight due to serving sizes and food preparation techniques.-make healthy choices when you eat out-might not be as healthy as choosing to prepare and eat meals at home Strategies...
SHARP Resources. SHARP CBT courses are an excellent resource for initial training as well as refreshers/cross-training of agency staff in these areas: SHARP Intro/Reporting. Time and Labor. Self Service, Timekeeper, HR Admin, Finance Maintenance . Human Resources. Workforce Admin, Position...
A computer/transceiver interface (if your radio requires one) WSJT-X software. Any modern Computer is adequate for FT8. However, the faster the better since a fast machine can decode much more quickly. Most modern ssb transceivers are good for ft8 as...
HSC approval of framework before NOFAs are developed and released allows program to be adaptable and responsive to policy priorities, programmatic changes and stakeholder needs. October 2019: first review of draft LIFT 3.0 framework,
Protecting Biodiversity. Captive Breeding. Mating animals in the zoo or wildlife preserves. Scientist care for the young and release them into the wild. Laws and Treaties. Endangered Species Act prohibits the killing or trading of endangered animals and/or products. Hard...
Ready to download the document? Go ahead and hit continue!