x = c E h (What atoms have to do with it)

Chapter 4 H Chem The Atom…cont’d

Bohr Model

(Proven by looking at Bright-Line Spectra)

Therefore

These are called:

Defined as:

Filling order for atoms with more than one electron

The observer affects the observed What DeBroglie said

Shown with:

1.

or

2.

The Rutherford Model could not explain…

The atom does not collapse The light emitted by atoms

Wave-like Particle-like

(Young…Double Slit)

wavelengthfrequency Speed of

light

3.0 x 108m/s

(Planck / Einstein)

Quantum of energy

Planck’s Constant… 6.6x10-34J•s

(Photo-electric effect)

(photon)

Bright-Line Spectra

For hydrogen:

electrons can have only certain energiescolors are emitted when electrons jump from higher to lower energy levels

For H: En=-1312 kJ mole e- n2

Wave Mechanical Model

Heisenberg’s Uncertainty Principle

If light has a dual nature…why not matter

SchroedingerElectrons are waves (Max Born)

…only certain energies allowed

Energy levels exist

Sub-levels exist

s p d forbitals

High probability regions in space where the electron is likely to be found

(1) (3) (5) (7) Aufbau

Pauli

Hund’s

Config.

Orbital

Electrons are waves of chance.

Determine the wavelength of light given off when an electron in the 9th energy level drops to the 8th energy level in hydrogen

Determine the wavelength of light given off when an electron in the 9th energy level drops to the 8th energy level in hydrogen

E9 = -1312 kJ/ 81 mol e- = -16.2 kJ/mol e-

E8 = -1312 kJ/ 64 mol e- = -20.5 kJ/mol e-

E = -20.5 kJ/mol e- - (-16.2 kJ/mol e-) =-4.3 kJ/mol e-

(4.3 kJ/mol e-)(1 mol e-/ 6.02 x 1023 e-) =7.1 x 10-24 kJ/ e-

energy released→

7.1 x 10-21 J = h 1.1 x 1013 / s = (1.1 x 1013 / s) = c = 2.7 x 10-5 m

7.1 x 10-21 J/ e-=

Compare the electron orbits of the Bohr model with the electron orbitals of the wave mechanical model

Electron orbits in the Bohr Model were paths etched out by the electrons as they circled the nucleus…the electron was viewed as a particle.

Electron orbitals are high probability regions in space where the electron is likely to be found. The regions are the result of the application of Schroedinger’s Wave equation to find were the electron position is knowing it possesses a certain amount of energy. There are many places of equal probability; hence a region instead of just one location (the electron cloud!)

Describe an orbital pair.Electrons with the same overall energy spinning in opposite directions.

What does it mean about the positions of the electrons in an atom when the electrons are in the ground state

Electrons in the ground state are in there lowest energy configurations.

Write the configuration notation for Cl

1s22s22p63s23p5

- (chlorine the ion)

6

How many unpaired electrons in the chlorine ion?) zero