CHEM6A - Fundamentals B, 1.1-1.3

CHEM6A - Fundamentals B, 1.1-1.3 - [nucleus])-The atomic...

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Fundamental B - - 1.1 The Nuclear Atom - J. J. Thomson discovered electrons and that they were part of the makeup for all atoms - Millikan’s oil drop experiment…each oil drop contained more than one electron, he took the smallest increment of charges between two electrons and that was determined to be one unit of positive charge (e) - e is referred to as the fundamental charge, e=1.602x10^-19 C, the charge on an electron is one unit of negative charge (-e) - J. J. Thomson measured the ratio of e/me, mass of an electron is 9.109x10^-31kg - Atoms have zero change, so scientists knew that you needed enough positive charge to cancel out the negative - Ernest Rutherford knew that elements emitted positively charged particles (alpha particles) - Geiger-Marsden experiment showed that not all alpha particles passes through the atom, suggesting the nuclear model (where there’s a dense, pointlike center
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Unformatted text preview: [nucleus])-The atomic number (Z) is the number of protons in the nucleus in each element; +Ze is the total charge on an atomic nucleusthere are also Z electrons around the nucleus for the atom to be neutral 1.2 The Characteristics of Electromagnetic Radiation-The analysis of the light emitted or absorbed by substances is called spectroscopy-Electromagnetic radiation is oscillating electric&magnetic fields that travel through empty space at the speed of light (c, 3.00x10^8m/s)-Forms of electromagnetic radiation include: visible light, radio waves, microwaves and x-rays (they all transfer energy from one region of space to another)-Ultraviolet radiation is radiation that is at a higher frequency than violet light, wavelength approx. <400nm-Infrared radiation is radiation experienced as heat, wavelength approx. >800nm-...
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This note was uploaded on 08/07/2009 for the course CHEM 6A taught by Professor Pomeroy during the Spring '08 term at UCSD.

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