Atomic Theory and the Periodic Table

Unit 2

electronegativity

ability to attract electrons in a covalent bond

Atomic Radius

distance from nucleus to the valence energy level

Johann Dobereriner

created the triads of similar elements

John Newlands

discovered the “law of octaves”

Dimitri Mendeleev

created first periodic table - based upon increasing atomic mass and similar properties

Henry Mosely

created modern periodic table - based upon increasing atomic mass and similar properties

The Aufbau Principle

Lowest energy orbitals are filled first

The Pauli Exclusion Principle

Orbitals can only contain 2 electrons, and when two electrons are in the same orbital they must have opposite spins

Hund’s Rule

Every orbital in a subshell is singly occupied before any orbital is doubly occupied, and all singly occupied orbitals have the same spin.

Principle quantum #

The energy level of an electron (1-7)

Angular momentum quantum #

the sublevels referring to shape

Magnetic quantum #

The atomic orbital the electron is located

Spin quantum #

Atomic Spin of an electron

Ground State

Electrons only in the lowest energy level (most stable)

Excited State

If any/all electrons move to a higher level

Excitation

Energy being absorbed for an electron moving to higher lever

Relaxation

Energy being released for an electron to move to a lower level

Photon

The energy being released during relaxation

Atomic Spectrum

Pattens of lines on the observed wavelength

2.998 × 10^8 m/s

Speed of light

E = hc/λ

equation that relates energy and wavelength, where E is energy, h is Planck's constant, c is the speed of light, and λ is the wavelength.

1/λ = Re((1/n,high) - (1/(n,low)))

Rydberg formula, used to calculate the wavelengths of spectral lines in hydrogen and other hydrogen-like atoms. n=principle quantum #, Re= Rydberg’s constant for an element

Periodic Table (1-Alkali metals, 2-Alkali Earth metals, 3-Transition metals, 4-Metalloids, 5-Halogens, 6-Noble gases, 7-Lanthanide S. 8-Actinide S. 9-Rare Earth)

Periodic Table

Ionazation Energy

amount of energy needed to remove 1e from neutral atom

Reactivity

ability of molecule or atomic to undergo chemical reaction, followed by a release in energy

Spherical

s-sublevel shape

Hourglass

p-sublevel shape

4 spherical shapes

d-sublevel shape

shapes vary

f-sublevel shape