Unit 3 Flashcards
- percentage of a given element’s available isotopes in nature
- dividing the average atomic mass of the element by the summation of isotopic masses
percent abundance
elements that have the same atomic no but diff mass no
isotope
formula for percent abundance
A = M1P1 + M2P2
A = average mass
M1 = mass of 1st isotope
P1 = percentage abundance of 1st isotope
M2 = mass of 2nd isotope
P2 = percentage abundance of 2nd isotope
atomic structure
electron shells
nucleus (proton+ & neutrons)
electron -
- depends on the atomic number
- identify if the atom is charged or uncharged
electron configuration
importance terms in electron configuration
main energy levels or shells
subshells
orbitals
valence electrons
- categorize electrons according to what orbital level in which they reside
diagonal rule
- no two electrons can have the same set of quantum numbers
- each atomic orbital can only accommodate 2 electrons (ex. 1s2)
pauli exclusion principle
lower energy levels are filled up first before filling the higher energy levels
aufbau building up principle
orbitals are filled up singly before pairing up
hund’s rule of maximum capacity
- father of modern chemistry
- developed the first true periodic table
- hydrogen
antoine laurent lavoisier
- proposed the LAW OF TRIADS
- Li, Na, K
- Ba, Ca, Sr
- S, Se, Te
- Cl, Br, I
Johann Dobereiner
- law of octaves (set of eight)
- properties of every 8 elements, starting from any element, are a repetition of the properties of the starting element only if they are arranged in ascending order according to their atomic masses
John Newlands
- first periodic law
- physical and chemical properties are periodic functions of their atomic weights
Lothar Meyer
Dmitri Mendeleev
- elements are arranged based on atomic numbers
- property varies with increasing atomic number
Henry Moseley
