CHEM 105N 1st Edition Lecture 11 Outline of Last Lecture I. ElementsII. Periodic Table of Elements- Periods and Groups- Metals, Nonmetals, & MetalloidsIII. Dalton’s Atomic TheoryIV. Subatomic Particles- Mass NumberV. Atomic Mass ScaleVI. Atomic Number- # of ElectronsVII. IsotopesOutline of Current Lecture I. Atomic MassII. Electromagnetic RadiationIII. Nature of Light- Electromagnetic Spectrum- Spectra- Atomic SpectrumIV. Electron Energy Levels- SublevelsV. Orbitals- DiagramsCurrent LectureI. Atomic Mass- (listed below the symbol of each element in the periodic table)- Gives the mass of an “average” atom in each element - Not the same as the mass number- Calculated using the weighted average- Weighted average: Mass (amu) x abundance (%)II. Electromagnetic Radiation- Energy that travels as waves through space- Described in terms of wavelength and frequency- Wavelength: distance per cycle These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.- Frequency: cycles per second (count peaks in wave)- Moves at the speed of light in a vacuumIII. Nature of LightElectromagnetic Spectrum:- Arranges forms of energy from low to high- Arranges forms of energy from long to short wavelengthsSpectra:- White light that passes through a prism - Separated into all colors all a continuous spectrum- Gives colors of the rainbowAtomic Spectrum:- Shows lines of different colors of light from a heated element passing through a prismIV. Electron Energy Levels- (Labeled as n=1, n=2, n=3… etc.)- Increase in energy as “n” increases- Lowest energy is closes to the nucleus - Electrons absorb energy to “jump” to higher energy level- Electrons emit energy when they “fall” to a lower energy level- Color is emitted (and visible on atomic spectrum) as electrons FALLSublevels:- Contain electrons with identical energy- Identified by letters “s, p, d, and f”- Number of sublevels in each energy level is equal to (n=?)Ex. N=3 3 sublevelsV. Orbitals- 3Dimentional space around nucleus where an electron is most likely to be found- Can hold up to TWO electrons (spin in opposite directions)- “S” Orbital: - spherical shape around nucleus- Increases in size around nucleus as “n” increases- ONE orbital- “P” Orbital:- Two-lobed shape- Increases in size around nucleus as “n” increases- THREE orbitals - “D” Orbital:- FIVE orbitals- “F” Orbital:- SEVEN orbitalsDiagrams:- Show orbitals as boxes in each sublevel- Electrons in boxes as UP or DOWN arrows- Electron in same orbital must have opposite
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