Unit 11 Chemistry

Democritus

Greek philosopher that said all matter is made of tiny particles called "atomos" or atoms

John Dalton

Billiard Ball Model \n 1. elements are composed of tiny particles, called atoms \n 2. all atoms of the same element are identical while atoms of different elements are different from one another (this is not true) \n 3. Compounds are composed of atoms from more than one element. The ratio of those elements are always whole numbers. \n 4. In a chemical reaction, atoms cannot be created or destroyed, they can only be rearranged, combined or seperated

Law of Conservation of Mass

Matter is not created nor destroyed in any chemical or physical change

JJ Thomson

\- discovered the electron using the cathode ray tube \n - plum pudding model

Marie Curie

\- Won two Nobel prizes \n -did pioneering work in radioactivity.

Ernest Rutherford

\-Nuclear Model of the atom, gold foil experiment- fired negative ions at thin sheet of gold foil, discovered the atomic nucleus and proposed a nuclear model of the atom

James Chadwick

Discovered/ confirmed the neutron

Niels Bohr

Planetary Model \n - electrons are allowed to travel in orbits so they don't fall into nucleus

what shape does s molecules look like?

sphere

what shape does p molecules look like?

dumbell

atomos

indivisible

wave

vibrating disturbance that transmits energy

photons

particles of light

c

speed of light

h

planck’s constant

max planck

\-German physicist who developed quantum theory and was awarded the Nobel Prize for physics in 1918 \n - not just a wave but also a particle-> quantum photon

electron configuration

the arrangement of electrons in an atom

Aufbau diagram

electrons fill lowest energy orbitals first \n \n 1s \n 2s 2p \n 3s 3p 3d \n 4s 4p 4d 4f \n 5s 5p 5d 5f \n 6s 6p 6d \n 7s 7p

Hund's Rule

electrons are placed into equivalent orbitals individually (with parallel spins) before they are paired

Pauli Exclusion Principle

no two electrons can have the same 4 quantum numbers

Atomic Radiusa

measure of the size of its atoms

trend top to bottom (atomic radius)

increases as you move down a column as there are more shells

Trend left to right (atomic radius)

decreases as you move across the periodic table from left to right

Electronegativity

A measure of the ability of an atom to attract electrons

trend top to bottom (electronegativity)

decreases as you move down

trend left to right (electronegativity)

increases as you move across a period

trend top to bottom (first ionization energy)

decreases as you move down group

trend top to bottom (first ionization energy)

decreases as you move down group

trend left to right (first ionization energy)

increases as you move across period

Coulomb's Law

Closer the particles are together -> the stronger the bond \n bigger the charge of particles -> the stronger the bond

effective nuclear charge

the net positive charge experienced by valence electrons (idk what this means)

what happens to frequency as wavelength increases?

frequency decreases

what happens to energy as the wavelength inceases?

energy decreases