Chapter 11- Modern Atomic Theory
The longer the wavelength of light...
...the lower the energy of its photons
Orbital Labels
1) The number tells the principal energy level 2) The letter tells the shape. The letter s means a spherical orbital; the letter p means a two-lobed orbital. The x,y, or z subscript on a p orbital label tells along which of the coordinates axes the two lobes lie.
Three properties of waves
1) wavelength 2) frequency 3) speed
process of emission of energy by atoms
1. atoms receive energy from some source 2. become excited 3. release energy by emitting light 4. emitted energy is carried away by a photon
Ernest Rutherford
1. nucleus is composed of protons & neutrons 2. nucleus is very small compared to entire size of atom 3. electrons revolve around the nucleus like the planets revolve around the sun
properties of wavelengths
1. wavelength 2. frequency 3. speed
Niels Bohr
1911 at age 25 received his Ph.D. in physics. Convinced that the atom could be pictured as a small positive nucleus with electrons orbiting around it. Was a mathematician. Struggled in school. Brilliant physicist. Awarded the nobel prize in physics in 1922.
Photons
A stream of tiny packets of energy
Schrodinger
Carried out a mathematical analysis based on this idea, he found that it led to a new model for the hydrogen atom that seemed to apply equally well to other atoms_something bohr's model failed to do
Line spectrum
Colors are in lines that separate narrow with some or all colors of the rainbow. Made by putting a gas, hydrogen, into a sealed tube. Each color of line is a different energy level.
Rutherford's Atom
Concept of a nuclear atom, Gold-Foil experiment, him and his coworkers were able to show that the nucleus of the atom is made up of protons and neutrons, found that the nucleus is apparently very small, suggested that electrons might revolve around the nucleus like planets around the sun
Bohr's Model of Atoms
Constructed a model of the Hydrogen atom with quantized energy levels that agreed with the hydrogen emission results. i fit the hydrogen atoms very well. Except when the model was applied to atoms other then hydrogen it did not work. It was fundamentally incorrect.
An atom can lose energy by _____________ a photon
Emitting
Quantized
Energy levels where only certain values are allowed. The energy levels of ALL atoms are __________.
Different wavelengths of electromagnetic radiation
Gamma rays, X-rays, Ultraviolet, Visible, Infrared, Microwaves, Radio waves
what couldn't rutherford explain?
He couldn't explain why the negative electrons aren't attached into the positive nucleus, causing the atom to collapse.
Energy can occur only in specific _____
Levels
Wave mechanical model
Modern model of the atom, shows the most probable location for an electron-called the orbital, and electrons have wave-like properties. Schrodinger and Broghe's model that could be applied to all elements, explained the periodic table, and introduced the concept of orbitals.
Core Electrons
The electrons in the inner shells of an atom; these electrons are not involved in forming bonds.
Atomic size
The size of an atom, usually measured by the radius
Ground State
When an electron is found at the lowest energy level
Continuous spectrum
White light that blends into another with all the colors of the rainbow
Type of electromagnetic radiation
X-Rays, Microwaves, Radio waves
Orbital Diagram
a electron configuration in which electrons are represented as arrows in boxes corresponding to orbitals of a particular atom. (aka BOX DIAGRAM)
Orbital
a representation of the space occupied by an electron in an atom; the probability distribution for the electron
Pauli Exclusion Principle
an atomic orbital can hold a max of two electrons, and those two electrons must have opposite spins.
Bohr theory
atom could be pictured as a small positive nucleus w/ electrons orbiting around it
excited state
atom with excess energy; can release some or all of its excess energy by emitting a photon->move lower energy state
A photon of RED LIGHT
carries less energy
x,y,z, subscript on p orbital label
coordinate axes two lobes lie
Bohr's suggestion
electron could jump to a different orbit by emitting a photon of light with exactly correct energy content
Valence Electrons
electrons on the outermost energy level of an atom
Metalloids
elements that exhibit both metallic and nonmetallic behavior semiconductors, border the zigzag line, shiny, brittle, hard, at high temp- good conductors of electric current
The energy contained in the photon corresponds to the change in _____ that the atom experiences in going from the excited state to the lower state
energy
electromagnetic radiation
energy is transferred from one place to another by light
Bohr's atom
energy levels in hydrogen atom represented certain allowed circular orbitals
ionization energy
energy required to remove an electron from an individual atom in gas phase
Metals
have a shiny or metallic luster, good conductors of heat and electricity
examples of electron radiation
holding your hand few inches from the light bulb; move close to wood in a fireplace; energy you feel from the sun
Speed
indicates how fast a given peak travels through the water
1s orbital
it describes the hydrogen electron's lowest energy state (the ground state)
atomic size decreases
left to right
Louis Victorde Broglie & Erwin Schrodinger
light seems to have both wave & particle characteristics (it behaves simultaneously as a wave & as a stream of particles), electron might also exhibit both of these characteristics
low energy photons
long wavelengths of light
metal properties
lustrous appearance; ability to change shape w/o breaking; can be pulled into a wire or pounded into a thin sheet; excellent conductivity of heat & electricity
A photon of BLUE LIGHT
more energy
neutrons
neutral particles
orbital level
number tells principle energy level; letter tells shape;
Different wavelengths of light carry different amounts of energy per ___________
photon
protons
positively charged particles
The atoms of elements in the same group (vertical column of the periodic table) have the _______ number of electrons in a given type of orbital (sublevel)
same
principle energy levels
series of energy levels. Labeled with integers. Each level is subdivided into sub-levels.
high energy photons
short wavelength
nucleus
small positive core of the atom
exceptions of atomic properties
solid iodine is lustrous; graphite form of carbon is an excellent conductor of electricity; diamond form of carbon is an excellent conductor of heat
s
spherical orbital
Electron configuration
the arrangement of electrons in an atom
electron spin
two electrons must have opposite spins to occupy same orbital
p
two-lobed orbital
atomic size increases
up to down
Frequency
v; indicated how many wave peaks pass a certain point per given time period (how many times a wave goes up and down per second)
Wavelength
λ; the distance between two consecutive wave peaks