Presentation on theme: "Cartoon courtesy of lab-initio.com. Neils Bohr I pictured electrons orbiting the nucleus much like planets orbiting the sun. But I was wrong! They’re."— Presentation transcript:
Cartoon courtesy of lab-initio.com
Neils Bohr I pictured electrons orbiting the nucleus much like planets orbiting the sun. But I was wrong! They’re more like bees around a hive.
Mathematical laws can identify the regions outside of the nucleus where electrons are most likely to be found. These laws are beyond the scope of this class…
You can find out where the electron is, but not where it is going. OR… You can find out where the electron is going, but not where it is! “One cannot simultaneously determine both the position and momentum of an electron.” Werner Heisenberg
As a direct result of Schrondinger’s equation, the first 3 quantum numbers were derived to show properties of –e in specific orbitals in which they are located in These equations paved the way for quantum theory describing mathematically wave properties of the –e and other small particles
1- main energy level 2-shape of orbital 3- orientation of orbital 4 th quantum number describes state of –e occupying the orbital (spin number)
Value-positive only- 1, 2, 3… 7 -e whose n=1 occupies lowest energy level (closest to the nucleus) Total number of orbitals existing in a shell (energy level) = n 2 All main energy levels has sublevels (suborbitals) of different shapes
Principle Quantum number Generally symbolized by n, it denotes the probable distance of the electron from the nucleus. “n” is also known as the Principle Quantum number Number of electrons that can fit in a shell: 2n 2
Orbital shapes are defined as the surface that contains 90% of the total electron probability. Electron Orbitals
Also known as azimuthal QN For specific energy level, the number of sublevels possible =n Value of 0 and all positive integers less than or equal to n-1 Examples: n=2, 2 shapes l =0 represents s l =1 represents p
s orbital- n=1- sphere p orbital- n=2- dumbell d- complex f- too complicated to discuss
The s orbital has a spherical shape centered around the origin of the three axes in space.
There are three dumbbell-shaped p orbitals in each energy level above n = 1, each assigned to its own axis (x, y and z) in space.
1 st energy level, n=1- only s orbital 2 nd energy level, n=2- only s and p 3 rd energy level, n=3- s, p and d 4 th energy level, n=4- s,p,d and f
Things get a bit more complicated with the five d orbitals that are found in the d sublevels beginning with n = 3. To remember the shapes, think of “double dumbells ” …and a “dumbell with a donut”!
1 s orbital-spherical only- 1 orientation (m=0) 3 p orbitals-3 orientations x,y,z (m= -1, m= 0, m= 1) and so on for d and f
5 d orbitals- orientation has values of m= -2, m= -1, m= 0, m= 1, m=2 representing dx 2 -y 3,dxy, dzy, dxz, dz 2 7 f orbitals-number of orbitals in each energy level equals n 2 If n=1, n 2 =1 or if n=3 then n 2 =9, etc
Value +1/2 or –1/2 Indicates fundamental spin state of the –e (-e spin on axis in one of two directions or states) Spin creates a magnetic field and accounts for the magnetic properties of –e (remember cathode ray and magnet)
Each orbital show by its principle QN followed by letter of suborbital 1s or 3p or 4d