Download The Modern Atomic Model

The Modern Atomic
Model
Bohr Model of the Atom (review)
•Energy levels contain electrons.
•Electrons travel around the nucleus.
•Different orbitals varied by different
quantum (energy).
•Gaps between energy levels were not
equal.
Electrons in Energy Levels
•All energy levels
above the
lowest energy
level are known
as “excited”
states or energy
levels. (n= 2, 3,
4 … etc.)
n=4
n=3
n=2
n=1
Erwin Schrödinger
•1926
•Created a math formula to explain how emoved.
(Schrödinger Equation)
•Schrodinger’s work focused on probability.
•Probability of finding an e- at various locations
around the nucleus.
•These “locations” are known as Atomic
Orbitals.
-
Quantum Mechanical Model (e cloud model)
•Nucleus (p+ and n0)
•Electron Cloud
•Cloud shows areas
of probable e
density
Quantum Numbers
•Quantum numbers describe the probable location of e- in
atoms.
•1s2
•‘principal quantum number’ (n) → The energy levels (n).
•[n= 1, 2, 3, 4, ….]
•The larger ‘n’, the further the e- is from the nucleus.
QM Model – Sublevels
• The 2nd quantum # represents the sublevel e- are found.
• sublevels contain the actual atomic orbitals (locations for e -)
• s-sublevel– 1 orbital, shaped like a sphere
• p-sublevel– 3 orbitals, shaped like a dumbbell
• d-sublevel– 5 orbitals, irregular shape
• f-sublevel– 7 orbitals, irregular shape
Shapes of Atomic Orbitals
Shapes of Atomic Orbitals
2s
Orbital Occupancy
•Each orbital, in each energy level can only
hold a maximum of 2 e-.
-
•s sublevel → 1 orbital, 2 e
•p sublevel → 3 orbitals, 6 e•d sublevel → 5 orbitals, 10 e•f sublevel → 7 orbitals, 14 e-
Sublevels and Occupancy (cont.)
•Not every energy level is made up of all the sublevels.
•N=1, contains ‘s’ only
•N=2, contains ‘s’ and ‘p’
•N=3, contains ‘s’, ‘p’, and ‘d’
•N=4…. , contain all 4 sublevels
Picturing the Atom
Spin Quantum Number
•Electrons are not only in motion based on their
velocities, they are also rotating.
•e- can either have a +1/2 or -1/2 for their ‘ms’
values.
1s