Clicker questionWhich of the following electron transitions in a hydrogen atom will result in theemission of light with the shortest wavelength?1A. n = 1 to n = 3B. n = 3 to n = 1C. n = 4 to n = 3D. n = 2 to n = 3E. n = 3 to n = 2shortest wavelengtheaEphoton=(hc)/wavelengthdelta E of the transition= EphotonSmallest wavelength=>high Ephoton=>largest delta EeaeUpcoming deadlines• Finish the “Week 1 Lectures 1-3” homework (due tomorrow at recitation). See “Homework Expectations” document on ANGEL. • Take the ANGEL Quiz 1 (due tomorrow by 11:55PM) • Read Lessons 03-1 to 03-4, including the reading guides , example problems , and stop signs before class on Fri. 9/4. • Finish up ALEKS!! (due Sun. 9/6)2(eBook)• Take the pre-test in the “CHEM 110 FA15 Grades & Conflict Sign-up Course” on ANGEL (due Mon. 9/7 by 11:55PM)• Take the “Intro quiz” on ANGEL (due Thurs. 9/10 by 11:55PM)Electronic transitions and emission lines• All electronic transitions that go down to nf= 1 will be in the UV range of the EM spectrum.• This is due to the fact that there is a very large energy gap between n = 1 and n = 2.• Electrons that undergo a transition through this large energy gap will release photons with high energy.• All electronic transitions that go down to nf= 2 will be in the visible range of the EM spectrum.• All electronic transitions that go down to nf= 3 will be in the IR range of the EM spectrum.• If we look at the Hydrogen emission spectrum (in the visible range), all wavelengths observed are only due to transitions that involve nf= 2.3Transition #:n = 2n = 3n = 4n = 5n = 6n = 1EnergyHigh E Low E1 2 3 41 2 3 4The Bohr model only works for one-electron atoms• Orbits do not really paint an accurate picture of the location of electrons.• In 1924, Louis de Broglie proposed that matter has dual wave/particle behavior, just like light.• Wavelength of matter waves: λ = hmv• The de Broglie wavelength is only significant for extremely small masses (like e‒).• For an e‒, the wavelength is on the order of the atom’s size. • For a baseball and bacteria,  is too small to observe.• The wave-like property of e‒s was proved in 1927.4http://www.clemson.edu/glimpse/wp-content/uploads/2012/09/Broglie_Louis_-Victor_de.jpghttps://tysontrepidations.files.wordpress.com/2011/07/pollen-under-scanning-electron-microscope.jpghttp://archives.starbulletin.com/1999/04/02/features/story2.htmlde BroglieScanning Electron Microscopy imagesConsequence for electrons in atomsThe wave-like nature of matter is important when dealing with subatomic matter.5The mass of the electron is well-known and the velocity can be determined, therefore: we can only calculate the probability of finding an e‒.The Heisenberg Uncertainty Principle: It is impossible to simultaneously know the exact position and momentum (mv) of a particle.The Schrödinger equation can be used to determine the probability of finding anelectron in a region of space (the “electron density”).These clouds of electron density are called orbitals.https://s-media-cache-ak0.pinimg.com/236x/80/d4/12/80d41204b641b13ac66f40814fb4f702.jpgOrbitals are described by three quantum numbers1. Principal quantum number (n) – size information2. Angular momentum quantum number (ℓ) – shape information3. Magnetic quantum number (mℓ) – orientation informationThe orbitals only exist if we have at least one electron in them. Orbitals only tell us where we are likely to find an electron.6same from Bohr modelThe principal quantum number (n)• The principal quantum number must be an integer greater than zero (n = 1, 2, 3…)• The principal quantum number (n) gives information about: The size of the orbital The energy associated with an electron in the orbital7n = 1 n = 2 n = 3as n increases, the size of orbital increasesas n increases, the energy increases(as e- are further away from nucleus, become less stable, higher E)The angular momentum quantum number (ℓ)• The values of ℓ depend on the principal quantum number, n.• For a given n, the possible values of ℓ include all integers from 0 to n ‒ 1.Examples:• If n = 1, • If n =3, • The angular momentum quantum number (ℓ) gives us information about ______• We use symbols instead of numbers for ℓ.8ℓ = 0 1 2 3Symbolspdfl=0 [n-1=1-1=0]l=-,1,2 [max is n-1=3-1=2]shapesphericaldumkbell4-leaf cloverMagnetic quantum number (mℓ)• The values of mℓdepend on the angular momentum quantum number, ℓ.• For a given ℓ, the possible values of mℓinclude all integers from ‒ℓ to +ℓ.Examples:• If ℓ = 1, • If ℓ =2, • The number of mℓ values tells you the ________________ with the given ℓ value.• The magnetic quantum number gives information about ____________.9n = 2m(l)= -1,0,1# of orbitalm(l)=-2,-1,0,1,2three p-orbitalsfive d-orbitalsorientationp-orbitals, l=1d-orbitals, l=2# OF ORBITALS= 2l+1• An orbital is described by _____ quantum numbers: _________________Examples: Shells, subshells, orbitals?• A shell is described by _____ quantum number: ____• A subshell is described by _____ quantum numbers: ___________Example: 3s subshell is defined by 10n= 1ℓ=mℓ=Subshell= n2ℓ mℓSubshellonen3rd shell: n=3n and ltwon=3, l=00threen, l, and m(l)01sone orbital: 1s010-1012s2pone orbital 2sthree orbitals 2p: 2px,2py,2pzYou should understand how to determine all these numbers and what they mean11Clicker questionWhich of the following set of quantum numbers is not permissible?12A.n= 2, ℓ = 1, mℓ= -1B.n= 3, ℓ = 2, mℓ= 2C.n= 2, ℓ = 0, mℓ= 0D.n= 4, ℓ = 3, mℓ= -3E.n= 3, ℓ = 3, mℓ= 0not permissiblebecause n-1=l => l cant be same as nSummaryOrbitals:• Are allowed energy states for electrons in an atom.• Describe spatial distribution of electrons in these energy states.13Orbital NameNumber of orbitalsShape s 1 sphericalp 3Dumb belld 5Clover leaff 7 ?!?!?!?!Quantum number:defines principalnsizeangularmomentum ℓshapemagneticmℓorientationClicker questionGive the n and ℓ quantum numbers that describe the following orbital. Assume it is in the third shell.14A.n = 1, ℓ = 2B.n = 2, ℓ = 3C.n = 3, ℓ = 3D.n = 3, ℓ = 1E.n = 3, ℓ = 2Orbital modified from http://en.wikibooks.org/wiki/High_School_Chemistry/Shapes_of_Atomic_Orbitals#/media/File:D_orbitals.pngQuantum numbers and nodes• A node is where there is zero electron density. The electron will never be found