Chapter 6 Flashcards
What is a wave?
A vibrating disturbance by which energy is transferred
Examples of waves
Microwaves, Ocean Waves
Properties of Waves
Wavelength
Amplitude
Frequency
Wavelength
Waves consist of alternating peaks and troughs separated by a constant amount
Amplitude
The heights of the peaks (or lows of the troughs)
Frequency
The number of peaks (or troughs) that pass by a certain fixed point in a certain amount of time
In a wave, what is mathematically related?
wavelength and frequency
Electromagnetic radiation
the transmission of energy in the form of electromagnetic waves
What is special about electromagnetic radiation?
Can travel through a vaccum
What is the smallest piece of light called?
Photon
Emission Spectrum
When large amounts of energy are provided to a substance, the substance releases that energy as electromagnetic radiation of certain frequencies
The specific frequencies given off are characteristic of the substance
What is the wavefunction?
Square is the probability of finding an electron in a certain region of space
Principal Quantum Numner
Corresponds to the one for the Bohr atom
It can take positive integer values (1, 2, 3, etc)
Angular Momentum Quantum Number
Gives the 3-D shape of the orbital
It can take on integer values from 0 to n-1
Designated by a letter
What are the letters for the Angular Momentum Quantum Number?
s, p, d, f, g, h
Magnetic Quantum Number
This quantum number describes the orientation of the orbital in space
The values of ml are integer values from -ℓ to +ℓ
Level
Collection of orbitals with the same value of n
Sublevel
One or more orbitals with the same value of n and ℓ
Subshell
Contain a single orbital or several orbitals
s Orbitals
s orbitals (ℓ = 0) are spherical in shape
The size of the orbital increases as n increases
The value (phase) of the wavefunction in all s orbitals is always positive
Larger values of n correspond to orbitals that have larger numbers of nodes (areas of zero electron density)
One node
p orbitals
p orbitals have ℓ = 1, therefore there cannot be any p orbitals with n = 1 (remeber n must be larger than ℓ), they start at the n = 2 level
Each p sublevel consists of three orbitals (mℓ = -1, 0, +1), they are generally called px, py and pz - there is no simple relation between the subscript and the value of mℓ
All three orbitals are identical in size, shape, and energy
p orbitals have a “dumb-bell” shape, with one lobe on either side of the nucleus
The value (phase) of the wave-function (positive or negative) is opposite on the two sides of the nodal plane
2 Nodes
d Orbitals
d orbitals have ℓ = 2, therefore there cannot be any d orbitals with n = 1 or n = 2, they start at the n = 3 level
Each d sublevel consists of five orbitals (mℓ = -2, -1, 0, +1, +2)
All five orbitals can expressed in a form so that they are identical in size, shape and energy … but they usually aren’t
2 Nodes
Maxwell
Visible light consisted of electromagnetic waves
Einstein
Used work on Photoelectric effect to show that under certain circumstances, light behaved more like particles
Balmer
Derived a formula to explain the position of the lines in the visible region of the hydrogen spectrum
Rydberg
Generalized Balmer’s equation to all regions (infrared and ultraviolet)
De Broglie
Linked Einstein’s idea about light having particle like properties with electrons
Davisson and Thomson
Showed that a beam of electrons could be diffracted by a sample in the same way as x-rays
Shrodinger
Derived equation tat describes the energies and movement of subatomic particles
Heisenberg’s Uncertainty Principle
It is impossible to know both the momentum and the position of a particle with certainty
