Chemistry - Electrons and Quantum Theory [Chapter 3]

Planck's Constant

h=6.626x10^-34 J*s

speed of Light

c=3.00x10^8 m/s

energy

J or Kg m^2/s^2

wavelength

[lambda] m

frequency

[nu] 1/s, Hz

eq for c

(nu)(lambda)

eq for E

(h)(nu); (h)(c)/(lambda)

de Broglie wavelength

(h)/(mass)(velocity)

momentum

(mass)(velocity)

eq for 1 Joule

= (1 kg)(mass^2)/(seconds^2)

photoelectric effect

electrons can be ejected/emitted when light interacts with/is shined on metal

energy of photon

(threshold energy) + (kinetic energy); (h)(nu)

kinetic energy

(1/2)(mass)(velocity^2)

nm to meter conversion

1 x 10^9 nm

Hz to MHz conversion

1 x 10^6 Hz

if light is below threshold energy level...

no electrons are emitted no matter the intensity of the light

if light is of a sufficient frequency...

as the intensity of light source increases, # of electrons ejected increases

as frequency is increased above the threshold...

velocity of ejected electrons increases

Planck's discovery

quantization of energy and its relationship to frequency

Bohr's discovery

electrons exist within distinct energy levels

Einstein's discovery

defined light as a particle to explain the photoelectric effect

Wave-Particle Duality

electrons have properties of both waves and particles

frequency and energy are...

directly proportional

wavelength and frequency are...

inversely proportional

energy and wavelength are...

inversely proportional

when electrons go from high energy to low energy...

visible light is emitted

electromagnetic radiation

light is the visible part of the vast spectrum of electromagentic waves

wave

an oscillation that can transport energy from one point to another

quantization

the act of expressing in terms of quantum theory

nodes

one or more points on a wave between the endpoints that are not in motion

Blackbody radiator

ideal emitter that approximates behavior of many materials when heated

endothermic

increases energy of an atom, involves absorption of light, endo=enter

exothermic

decreases energy of an atom, involves emission of light, exo=exit

line spectra

light having narrow widths interspersed throughout spectral regions

quantum numbers

integer numbers having only specific allowed values and used to characterize the arrangement of electrons in an atom

atomic orbital

a general region in an atom where an electron is most likely to reside

electronic spin

quantum phenomenon that describes an intrinsic rotation, angular momentum of an electron

Hund's Rule

maximize parallel spin in a sublevel

Pauli Exclusion Principle

no two electrons in an atom can have exactly the same energy level, sublevel, orbital, and spin

cation

atom that has lost electrons, positive charge

anion

atom that has gained electrons, negative charge

Aufbau Principle

electrons occupy the lowest available sublevels

half-full -- half-full Aufbau Exception

Chromium (Cr), Molybdenum (Mo)

half-full -- full Aufbau Exception

Copper (Cu), Silver (Ag), Gold (Au)

electromagnetic radiation travels most quickly through...

vacuums