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