Go to lab and recitations, srsly Assignment: Read chapter 1 Look up: Solid, liquid, gas, molecule Need lab notebook, something to make copies, like physical carbon paper Units and measurements Table: Physical quantity Name Abv -------------------------------- Mass Kilgram kg Length Meter M Time Second S Temperature Kelvin K Amount Mole mol Current Ampere A Luminosity Lumen Cd Prefix Abv Meaning ------------------------------- Deci d 10^(-1) Centi c 10^(-2) Milli m 10^(-3) Micro u 10^(-6) Nano n 10^(-9) Pico p 10^(-12) Femto f 10^(-15) Kilo k 10^(3) Mega M 10^(6) Giga G 10^(9) Derived qty Name Symbol ----------------------------------- Area Square meter m^2 Volume Cubic meter m^3 Density Mass per vol kg/m^3, g/cm^3 preferred Celsius Temp Deg Celsius oC Farenheit Temp Deg Farenheit oF 1m^3 = 1000L 1cm^3 = 1 mL 273K = 0C = 32F 373K = 100C = K = C + 273.15 F = 9/5C + 32 Units: 7, "SI units: System Internacional" Uncertainty Everything needs a unit of measurement, precision, and accuracy Precision: How close the values are to each other Accuracy: , precision, and accuracy Uncertainty: Accuracy Significant Figures Balances in the lab are good to 0.0001g Zero's on the left don't count, even if decimal Use the least significant value's precision Dimensional analysis Need conversion factors Everything is under course documents Objectives for Ch 1,2 Cathode Ray Tube Electricity moves from cathode to the anode Called a 'cathode ray' Coating of zinc sulfide doing the fluorescent Cathode ray bends down when a negative source is applied to the top Cathode ray bends up when a positive source is applied to the top Cathode rays are negatively charged Cathode rays = electrons Guy figured out charge-to-mass ratio of electrons was 1.76 * 10^8 coulon/gram coulon = Amp/sec Robert Millikin Invented tube with bottle on the end. Put oil in the container` Had viewfinder Opposite side had an x-ray Charge was 1.6*10^-19 coulons 9.1*10^-28 g is mass of electons Radioactivity The spontaneous emission of particles and/or radiation Henri Becquerel - Coined 'radioactivity' - French Marie Curie - Polish, came to Henri's university to work with him Pierre Curie Curies found polonium and radium Earnest Rutherford - New Zealand Put uranium in a box Hole in the box Hole goes down tube to meet fluorescent screen Puts positive/negative power supplies, some bend up on a screen Electrons are attracted to positive side Electrons called beta particles, fro From nucleus Charge of -1 Called Beta particles Protons He4 nucleus Charge of +1 Stuff in the center Center dots are radiation, gamma particles Another experiment Stuck gold foil in a circle around screen Atom was mostly empty space with a small hard center Thompson Atom is big sphere of positive charge -1.602 * 10^-19 coulons = charge of electron 1.602 * 10^-19 coulons = charge of proton 0 = neutron Appartus with uranium in a box, then cone pointed at a screen with gold foil on it Alpha particles are transfered through come onto screen(+ charges) Atom Center - volume occupied by an electron Positive part - proton James Chadwick Englishman Instead of using gold, he used Beryllium He found particles coming out that had no charge Proved existence of neutrons Atomic mass unit Abreviated AMU 12 Atomic Mass Units = 1 Carbon-12 atom 1 AMU = 1/12th carbon-12 atom Particles Charge Mass in AMU e- - 1.0073 n 0 1.0087 p + 5.846 * 10^-4 ^ Don't write this on a notecard, given to us Each element has 3 types Atomic number: number of protons Atomic number to the lower-left of the symbol Mass number to the upper-left of the symbol Carbon 13: 6 protons, 6 electrons, 7 neutrons Carbon 14: 6 protons, 6 electrons, 8 neutrons Mass spectrometers measures atomic mass(35 v 37 in chlorine), uses a rounded corner and magnets, heavier stuff doesn't bend as much Stuff on the right are nonmetals Stuff on the left are metals Periodic table First column, Alkali metals Second: Alkaline earth metals 4-row sections and ladder: Transition metals Appended rows: Lanthanides and Achinides Hydrogen doesn't have any neutrons Sections 2.8, 2.9 won't be on the exam Molecular formula Gives a number and type of atoms in the molecule C4H8O2 C2H4O - Empirical formula Diatom - 2 atoms Ionization - sign means it has more electrons + sign means it has more protons Noble gasses Mostly inert Halogens Love to lose an electron Oxydation state Chlorine: -1 MG 2+ + 2Cl- = MgCl2 AKA Ionic compounds Chapter 6 Electronic Structure of Atoms Electromagnetic radiation - Visible region Wavelength of light = crest to crest of waves Wavelength of light = Lambda Lambda = 1/V Frequency(V) = nu 6.626 * 10^-34 Joules C = speed of light C = 2.99*10^8 meters/sec C = 3 * 10^8 m/sec Lambda = C/nu E = h * c/Lambda Isoelectronic - same number of electrons Number in lower left plus number in upper right What is the energy of 550kHz? Wavelength? Lambda = C/nu -3.0*10^8 wavelength 5.5*10^5 cycles per second Answer = 545 meters 3*10^8m/s / 1*10^5 sec^(-1) Max Planck Studied black body radiation Discovered there is a relationship between energy and frequency coming off of i E = h * nu h = plancks constant = 6.626*10^-34 J*s Photoelectric effect Light hits a piece of metal and sends off electrons Line spectrum: Discrete frequencies Niels Bohr Looked at lines of color, tried to explain Came up with the idea of orbits around nucleus Energy goes down the shells to the nucleus, then comes back up. Known as emission. Refractive index Compared to speed of light in a vacuum(constant) Hydrogen energy level diagram When energy is put in, it must step up a whole step, no partial movement up the diagram Steps are known as quantized Short arrow = infrared Speed of light * Plancks constant * R_h R_h = Rydberg Constant = 1.096776 * 10^7 m^-1 Interested in Delta-E, change in energy Delta-E = Final - initial Delta-E = -hcR_h(1/n_1^2) - (-R_h(1/n_1^2)) Delta-E = -hcR_H [(1/n_f^2) - (1/n_i^2)] n_f=3, n_i=2 Delta-E = 2.18*10^-18 J ](1/3^2) - (1/2^2)] Delta-E = 3.02*10^-19 J (1 / Wavelength) = Wave Number Louis DeBroglie Lambda = h / (mass * velocity) = h/(mv) mv = momentum Theory of wave particle duality Heisenbergs uncertainty principle Impossible to know the position Best proximity is h/(4pi) Delta-H for an electronic is 10^-10 meters Delta-H for an H atom = 10^-9 meters Irwin Schroedinger German physicist Psi Provides information about the position of an electron in space Dots on a 2 dimensional graph: probability of findning an electron Probability of findings dots together Psi = f(n, l, m_l, m_s) = principle quantum number n = 1 to inf = scale n = how far away thing is l = angular momentum l = shape l = [0..(n-1)] m_l = magnetic quantum m_s = spin Orbital shape n=1 l=0 n=2 l=1,0 n=3 l=2,1,0 n=4 l=3,2,1,0 ... Probability of finding an electron somewhere in an atom E = h*nu WRITE DOWN EQUATIONS Schrodingers wave question l = shape = corvallis n = oregon m_l = orientation = street P-orbital m_s = +1/2 or -1/2 = front/back of house No 2 electrons will have exactly the same quantum numbers, m_s must be different Electron configurations 5s 5p 5d 5g h = 1s^1 He = 1s^2 Li = 1s^2 2s^1 Be = 1s^2 2s^2 B = 1s^2 2s^2 2p^1 C = 1s^2 2s^2 2p^2 N = 1s^2 2s^2 2p^3 O = 1s^2 2s^2 2p^4 Fl = 1s^2 2s^2 2p^5 Bonding Done by 'valence electrons' Others are called 'core electrons' CuAr 4s1 3d10