# Chemistry ch 5

 Properties are determined by electrons That particles of matter have the same properties of waves & vice versa deBroglie deBroglie's equation E=mc2 (einstein) E=hv (Planck) c=yv / v=c/yhv=mc2, so hc/y=mc2, so y=hc/mc2, c's cancel and y=h/mc Wave-particle duality A stream of electrons acts the same as waves of light How was wave-particle duality proved mathematically by deBroglie's equations C=3x10^8 in a VACUUM. But, how does it travel elsewhere? It travels at different speeds and changes directions (refracts) Index of refraction specific to a substanceCalculated by the bending of a light ray passing from a vacuum into a new substance. Momentum Pmass x velocityTells where an object is goingSince y = h/mv, y = h/p As the momentum of an object increases, y decreases As the momentum of an object decreases, y increases. To see an object, It must be hit by a photon of light & reflected to our eyes. Uncertainty Principle you can't ever know the exact position and momentum of a moving object at any given instant. You can't ever see the exact position of an electron because The photon is deflected, but the electron is so small that it causes the electron to move. Uncertainty Principle by Heisenerg Who treated the electron as a particle? Schrodinger Theory of Quantum Mechanics SchrodingerStudies the behavior of very small objects travelling at velocities at or near the speed of light Newtonian Mechanics Newtonstudies the behavior of VISIBLE objects travelling at ORDINARY velocities. Who proved the planetary theory wrong? Schrodinger Orbitals 3-dimensional regions around the nucleus that give the probable location of the electron Quantum Numbers tell us The most likely position of the electron in an electron cloudSpecific properties of the orbitalsProperties of the electrons in the orbitals Primary Quantum Number nMAIN ENERGY LEVEL occupied by the electronvalues from 1-7, 1 is the smallest and closest to the nucleusas n increases, the energy of the electron it contains increases, as doesthe distance from the nucleus.2xn^2 = maximum number of electrons an energy level can hold. Second Quantum Number cursive l/ribbonSUBLEVEL and SHAPE of the orbital Number of sublevels in an energy level = nExcept in n=1, sublevels of different shapes exist in the same energy level Third Quantum Number (m) ORBITALS and SPATIAL ORIENTATION of the orbitals in a sublevel n^2 number of orbitals in an atom Orbitals in s 0 Orbitals in p 1 Orbitals in d 2 Orbitals in f 3 Sublevels s p d f cursive l=0 s cursive l=1 p cursive l=2 d cursive l=3 f Electron configurations are in what state? ground Outermost energy level atoms with full s and p levels (8e) Octet 8e. Very stable. Rules for filling energy levels with electrons 1. Aufbau Principle2. Pauli Exclusion Principle3. Hund's Rule4. Diagonal Rule Aufbau Principle electrons occupy the lowest energy orbital that can recieve it. Pauli Exclusion Principle No 2 electrons in the same atom can have exactly the same 4 quantum numbers. Hund's Rule Orbitals of equal energy are each occupied by 1 electron before any orbital is occupied by a second electron. All electrons in singly-occupied orbitals must have the (spin) same spin Diagonal Rule After 18 electrons have been assigned to the orbitals, the normal filling under rule one doesn't apply. Notations to show how electrons are arranged Electron configuration notationOrbital notationElectron dot diagramNoble gas notation Electron configuration notation levels with exponent 1s^2 2s^2 2p^6, etc. Orbital notation Levels with arrows Electron dot diagram Write the symbol for the elementIdentify elements in the HIGHEST ENERGY LEVELDoesn't matter which order the dots are in Noble gas notation Write the symbol for the noble gas which PRECEDES the element in brackets & then list the additional electrons the element contains after. [AR]4s^2 3d^10 4p^4 AuthorAnnaIsCool ID45164 Card SetChemistry ch 5 Descriptionchapter 5 Updated2010-10-28T01:03:37Z Show Answers