Presentation on theme: "Warm Up8-28-14 1.Find the volume of an object with 4 g/cm 3 and weight 40 g. 2.Explain why regular coke sink and diet coke float when placed in water 3.Water."— Presentation transcript:
Warm Up Find the volume of an object with 4 g/cm 3 and weight 40 g. 2.Explain why regular coke sink and diet coke float when placed in water 3.Water has a ratio of 2 Hydrogen atoms to 1 Oxygen atom. What law explain this? 4.Which part of Dalton’s atomic theory is false? Homework Aug 29 - Online HW Sept 3 – Element Project Bring pennies Agenda Turn in labs Test Chp 1 Notes Chapter 3-2 Element Project & Notebook
Test Chp 1 Do not write on the test Bubble your ID #, record your Version ID and Name on the answer document Multiple choice #1-24 Free response #25-26 – No calculators
Chapter 3-2 Structure of Atoms
Thompson’s Experiment J.J. Thompson a physicist that created the CRT (cathode-ray tube) To study current
Thompson’s Experiment CRT cathode electrode has negative charge anode has positive charge Glowing beam come from the cathode end Deflected by a magnet = beam has a charge
Thompson’s Experiment The Electron The CRT beam moved a paddle wheel Electron consists of particles that have mass and a negative charge -Note: e- are negatively charged but atoms have no charge, therefore atoms must contain + charge to balance the charges
Thompson’s Experiment “Plum Pudding” atomic model
Rutherford’s Experiment Rutherford conducted gold-foil experiments and discovered the nucleus.
Rutherford’s Experiment Only a positively charged particle could repel the positively charged alpha beam The mass of this particle has to be larger than the incoming beam to deflect it Most of the atom is empty space that’s why only some beams were deflected
Subatomic Particles The nucleus is made up of protons and neutrons Proton: has a positive charge Electron: has negative charge Neutron: no charge. A neutral atom has no net charge, means # of protons = # of electrons.
Current Atomic Model Changes to Dalton’s atomic theory
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Assignments Notes Summary Worksheet chp 3-2 front side and Element poster due Wednesday Bring pennies