Quantum Atom. Louis deBroglie Suggested if energy has particle nature then particles should have a...
Transcript of Quantum Atom. Louis deBroglie Suggested if energy has particle nature then particles should have a...
Quantum Atom
Louis deBroglie
Suggested if energy has particle nature then particles should have a wave natureParticle wavelength given by
λ = h/ mv
mv is momentum (mass x velocity)Called matter waves
Matter Wave
Wavelengths of ordinary sized objects are too small to notice
In smaller particles (like electrons) the wavelength becomes significant
What is the λ of an electron with a velocity of 5.97x106 m/s and a mass of 9.11x10-28 kg?
Electron Location
If a subatomic particle exhibits wave properties, we cannot know precisely where its location is
The wave nature of the electron extends it out in space
Uncertainty Principle
Werner Heisenberg suggested that we cannot simultaneously know both the location and momentum of an electron
Pointless to talk about the position of an electron
Quantum Mechanics
Describes mathematically the properties of an electronWave function (Ψ2) – series of solutions that describes the allowed energy levels for electronsShows regions of probability of finding an electronRegions of high electron density have large values of Ψ2
Quantum Numbers
Orbital – allowed energy state for an electron
Principal Quantum Number (n) – same as the Bohr energy levelAlso called shellsRange from n=1 to n=7
Azimuthal Number (l) Called subshellsThe maximum value of l is one less than n l=0 s subshell (spherical) l=1 p subshell (dumbbell) l=2 d subshell (four lobes) l=3 f subshell
Magnetic Quantum Number (ml )These are the orbitals (hold 2 e- each)Range from – l to + l s ml = 0 ( 1 orbital)
p ml = -1, 0, + 1 ( 3 orbitals)
d ml = -2, -1, 0, +1, +2 (5 orbitals)
f ml = -3, -2, -1, 0, +1, +2, +3 (7 orbitals)
Example
Predict the number of subshells in the fourth shell. Give the label of each subshell. How many orbitals are in each?