Presentation on theme: "Unit 2B Notes: Electron Configuration Ch 6"— Presentation transcript:
1 Unit 2B Notes: Electron Configuration Ch 6 DuntonHonors Chemistry
2 Newton- light consists of wave & particle properties Waves- light is made of electromagnetic radiation Wavelength- distance from trough to trough, in m Amplitude- distance from top to base line Frequency- # waves past a point per unit time, v· Measured in Hz (hertz) = s-1 = 1/s
4 Speed of light- how fast all light goes, c · c= 3.00 X 108m/s· c = vRemember v is frequency in Hz or 1/s and is wavelength in m (you may have to convert!)** Notice that wavelength & frequency are inversely proportionalFind the wavelength if the frequency is 5.10 X 1014 Hz.
5 Know this in order!! Electromagnetic spectrum: Radio Micro Infrared Visible UV X-ray GammaroygbivHigh wavelength () Low Low frequency (v) High vLow E High E
7 6.2 Planck- energy is emitted and absorbed in packets (quanta) Explains line spectrumE=hvh= Planck’s constant X Jsv = frequency, Hz, 1/s, s-1E proportional to v(frequency)Find the energy if the frequency of 5.00 X1015Hz.Find the wavelength of radiation if the energy of the wave is 2.66 X J. Use the chart on pg 276 to find the type of radiation.
8 Einstein- light in quanta= photons E of photons is quantitizedPhotoelectric effect- metals eject e- called photoelectrons when light of a high E shines on them Purple light has high v to have high E & can eject e- Red light has low v so low E & can’t eject e- If you want to increase E that will increase the speed of e- If increase intensity, just increases # of e- not speedEx. Solar calculators
9 7.2 Can find color or type of emission based on & v Emission spectrum- colored lines characteristic of elementsØ Atoms absorb E then lose E give off lightØ Can use this to ID elementsContinuous spectrum- all colors (white light)Line Spectrum- specific colors, based on elementUsed to ID contents of stars & planets
10 7.4Bohr’s Model: electrons orbit the nucleus; only orbits in certain energies are permittedGround State- lowest E levelExcited State- Higher than ground stateThe e- are raised to the next level, then release light when they return to ground stateMust have enough E to raise to next level or won’t happen
11 6.4 DeBroglie-Quantum Mechanics- light behaves as wave & particles = h/mv= wavelengthh= Planck’s constantm=massv= velocityVisible objects (baseball) have too small to see, need very small object to detect Heisenburg Uncertainty Principle- Can’t know the position & speed of electron at the same time
12 Energy levels- region around nucleus where e- likely to be found (electron density is high) 90% Quantum- amount of E for e- to jump levelsContinuous- ramp, no unitsQuantitized- fixed levels, fixed units
13 Flame Test Lab Sc3fPurpose: In this lab the student will observe light spectrum emitted from heated metal ions and calculate the frequency, wavelength and energy.Materials: salts, bunsen burner, Q-tipsSafety: Wear goggles & apron. Wash hands & wipe down lab station after use.
14 Procedure:1. Get two beakers of water. Label one “clean” and one “dirty”.2. Dip the Q-tip into the “clean” water3. Dip the Q-tip into the salt4. Put the Q-tip into the flame5. Record the color6. Swish the Q-tip into the “dirty” water and leave it there.7. Repeat with clean Q-tip for each sample.Observations: Create your own table with salt and color. There are 7 samples.
15 Conclusion: 1. Draw and label the parts of the atom. 2. Explain what happened on the atomic level in this lab.3. How does the flame test provide support for quantitized energy levels? Explain.4. List the metal ions present in your unknown solutions and provide reasons for your choices.5. For each salt use the color to estimate the wavelength from the chart in your book. Use the wavelength to solve for the frequency and energy.
16 Schrodinger- estimates the probability of e- to be in certain area; uses wave and particle like properties to create quantum mechanics (a series of wave functions and mathematical equations) A fuzzy cloud, more dense= more likely to find e- 90% of the timeOrbitals-Wave functions with corresponding densities (shape and energy)**orbital is NOT the same as Bohr’s orbit
17 Quantum Numbers: 1. Principle Quantum Number- (n) 1-7 Same as period, tells number of levels; the higher the number the further from the nucleus2. Second Quantum Number aka the azimuthal quantum number -(l) determines shapeSublevels- same as # of n, shape of orbital s- sphere l =0 p- dumbbell l=1 d- complex l=2 f- complex l=3
18 Correlation of n & l Level (n) Sublevels (l) Sublevel Called 1 s 2 s, p3s, p, d4s, p, d, f
19 Quantum Numbers3. Magnetic Quantum Number-ml describes orientation of orbital in space can be any number from –3 to 3 or zero4. Electron spin quantum number- ms describe the direction of the electron spin producing a magnetic field; 2 opposite magnetic fields allow for close spacing; +1/2 or – 1/2
20 electron shells - Collection of orbitals with same n value Subshell- set of orbitals with same n & lOrbital- Each orbital can hold 2 e-Formula for total number of orbitals =n2Sublevel (l)Possible values of ml# Orbitals# Electronss12p1,0,-136d2,1,0,-1,-2510f3,2,1,0,-1,-2,-3714
21 6.7Pauli Exclusion Principle- Because e- are negatively charged, and they repel each other, w/in an orbital one goes clockwise & one spins counter clockwise; no two e- can have the exact same set of quantum numbersEach electron has an “address”:Principal quantum number (n)Sublevel (l)Orbital (ml)Spin (ms)
22 Electron Configuration- way e- arranged around atom, each e- address Using the PT:The principal quantum number for the outer electrons is the same as the period.There are blocks: s, p, d, fNoble gases have a full s & p level making them inertAlkali Metals- s1Alkaline Earth Metals- s2Transition Elements- outer s & inner dInner Transition Elements- outer s & inner f
23 Electron Sequence by the Periodic Table LaAc5f4f2s3s4s5s6s7s2p3p4p5p6p3d4d5d6d
25 Electron Orbital Diagram: visually shows e- placement around the nucleus Each orbital gets own boxOrbital# Orbitals# electrons held# boxess12p36d510f714
26 Basic Rules to remember: Aufbau Principle- e- enter the lowest energy level 1stPauli Exclusion Principle- an orbital can only describe 2e-,Show each orbital w/its own boxOne is spinning clockwise & the other is counter clockwise,Show this with one arrow going up & one pointing downNOT
27 Hund’s Rule- e- w/ same spin must occupy each E level in a sublevel before doubling up Example: when filling the p sublevel with 4e-, each box gets 1 before doubling up one boxNOT
28 Aufbau Exceptions: Cr, Cu, Mo, Au, Ag Want full or ½ full orbital and can shift e- to get itEx: s2d4 s1d5s2d9 s1d10
29 Electron Sequence Model Follow the yellow brick road1s2s3s4s5s6s7p6p5p4p3p2p6d5d4d3d4f5f7s
33 Electron Configurations ScKPB1s2s2p3s3p4s3d4p1s2s2p3s3p4s3d4p1s2s2p3s3p4s3d4p1s2s2p3s3p4s3d4p
34 Noble Gas Configuration Go back to the last noble gasWrite symbol for noble gas in bracketsWrite rest of configurationNa Complete Configuration:1s22s22p63s1 Na Noble gas Configuration:[Ne] 3s1 Exceptions to electron configuration:e- want to be stableStable is a full or ½ full e- shellCr- [Ar] 4s23d4 [Ar] 4s13d5Cu- [Ar] 4s23d9 [Ar] 4s13d10
35 8.1 Valence electrons- e- in outer most level Put in noble gas configurationCount e- in highest levelEx: Na 1s22s22p63s1 has 1 valence e-Cs [Xe] 6s1 has 1 valence e-Cu [Ar] 4s13d10 has 1 valence e-S [Ne] 3s23p4 has 6 valence e-Lewis Dot Structures- shows valence e- around symbol Li N Be O B F C Ne