Class Notes (807,339)
Canada (492,708)
Chemistry (406)
CHEM 1040 (192)

Atomic Structure and Periodic Trends: Lectures during Week 1-2

5 Pages
Unlock Document

University of Guelph
CHEM 1040
Adrian Schwan

Atomic Structure Light and Spectroscopy The interaction of atoms or molecules with light is well documented: Examples include heated metals that give off light, ambient light effects, chemiluminescents, light bulbs, glow in the dark material. Important clues to the structure of atoms can come from analyzing emmisions or absorption of heat by atoms. Light: Fluctuating electric and magnetic fields that are perpendicular to the motion of the wave and to eachother. Possesses energy defined in formulaic form as: ×v carrying units of Joules (J) Described in terms of wavelength and frequency h is Planck's constant -34 h = 6.63 x 10 J s Planck proposed that electromagnetic irradiation come in packets of defined energy. Therefore light is quantized. Units: c m s , λm, v  s -1 "c" is the velocity of light: 300000000m/s in a vacuum The unit s = 1/s = reciprocal time (“per second”) Given the special name hertz, abbreviated Hz : 1 Hz = 1 s -1 (also know as cycles per second) Example: What is the frequency of yellow light of wavelength 625 nm? c = λ×v v = c/λ nm = nanometer = 10e-9 so 625 nm = 625e-9 m v = 3.00e8 m/s / 625e9 m v = 4.8e14 Hz de Broglie suggested that the movement of small particles such as photons could be described as waves Schrödinger set up the equations to describe wave motion of atoms. Part of these equations are quantum numbers which define energy and 3-dimensional position of electrons in space. (where finding an electron is of high probability) Quantum Model (sub-orbits within orbits) S – holds max 2 electrons P – holds max 6 electrons d – holds max 10 electrons f – holds max 14 electrons Principal quantum number n - represents the main energy level of an electron - higher n value means it is further away from nucleus and the orbitals have higher energy - permitted values of n are 1,2,3,4…etc - represented by a letter K,L,M,N  Angular Momentum quantum number l - divides shells into smaller subshells - helps define the shape of the orbital/electron cloud - l = 0, spherical shape (S orbital) - l = 1, dumb-bell shape (p orbital) - l = 2, variety of shapes (d orbital) - permitted values of l range from 0-(n-1) i.e. n=4, l=0,1,2,3 MAGNETIC Quantum Number m l - indicates permitted orbitals/group - range for ml= -l to +l - m lpecifies the permitted orientations in space of an electron cloud - It tells you how many sub-levels there can be for any l value Spin Quantu
More Less

Related notes for CHEM 1040

Log In


Don't have an account?

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.