Class Notes (839,626)
United States (326,062)
Chemistry (186)
CHEM 1030 (81)

chem1030 chapter 6 notes: electronic structure of atoms

6 Pages

Course Code
CHEM 1030
Marla Spergel

This preview shows pages 1 and half of page 2. Sign up to view the full 6 pages of the document.
Chapter 6: Electronic Structure of Atoms  Waves o The distance between corresponding points on adjacent waves is the wavelength (). o The number of waves passing a given point per unit of time is the frequency (). o For waves traveling at the same velocity, the longer the wavelength, the smaller the frequency.  Electromagnetic Radiation o All electromagnetic radiation travels at the same velocity: the speed of light (c), 8  3.00  10 m/s. o Therefore, c =   The Nature of Energy o Max Planck explained it by assuming that energy comes in packets called quanta. o Einstein used this assumption to explain the photoelectric effect. o He concluded that energy is proportional to frequency:  E = h  where h is Planck’s constant, 6.626  104J-s. o Therefore, if one knows the wavelength of light, one can calculate the energy in one photon, or packet, of that light:  c =   E = h o For atoms and molecules one does not observe a continuous spectrum, as one gets from a white light source. Only a line spectrum of discrete wavelengths is observed. o Niels Bohr adopted Planck’s assumption and explained these phenomena in this way:  Electrons in an atom can only occupy certain orbits (corresponding to certain energies).  Electrons in permitted orbits have specific, “allowed” energies; these energies will not be radiated from the atom.  Energy is only absorbed or emitted in such a way as to move an electron from one “allowed” energy state to another; the energy is defined by E = h  The energy absorbed or emitted from the process of electron promotion or demotion can be calculated by the equation:   where R is the Rydberg constant, 2.18  1018J, and n and n are the H i f initial and final energy levels of the electron.  The Wave Nature of Matter o Louis de Broglie posited that if light can have material properties, matter should exhibit wave properties. o He demonstrated that the relationship between mass and wavelength was   The Uncertainty Principle o Heisenberg showed that the more precisely the momentum of a particle is known, the less precisely is its position known:  o In many cases, our uncertainty of the whereabouts of an electron is greater than the size of the atom itself!  Quantum Mechanics o Erwin Schrödinger developed a mathematical treatment into which both the wave and particle nature of matter could be incorporated; known as quantum mechanics. o The wave equation is designated with a lower case Greek psi (). 2 o The square of the wave equation,  , gives a probability density map of where an electron has a certain statistical likelihood of being at any given instant in time.  Quantum Numbers o Solving the wave equation gives a set of wave functions, or orbitals, and their corresponding energies.  Each orbital describes a spatial distribution of electron density.  An orbital is described by a set of three quantum numbers.  Principal Quantum Number (n) o The principal quantum number, n, describes the energy level on which the orbital resides. o The values of n are integers ≥ 1. 
More Less
Unlock Document

Only pages 1 and half of page 2 are available for preview. Some parts have been intentionally blurred.

Unlock Document
You're Reading a Preview

Unlock to view full version

Unlock Document

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.