Exam

Pauli exclusion principle
two electrons per orbital
Aufbau

electrons occupy the lowest level or energy

Hund’s Rule

– electrons occupy equal energy orbital’s so that a minimum number of unpaired electrons

Newlands
based his table on music
Mendeleev

arranged the table by atomic mass

Bohr
proposed the existence of energy levels
Rutherford
couldn’t explain the chemical properties of elements
Dobenreiner
arranged elements into triads
Ground

1s^2 2s^2 2p^6 3s^2

Excited-

1s^2 2s^2 3s^1 3p^1

Impossible

1s^2 2s^3 2p^6 3s^1

In the forth quantum there are four sublevels called

S,P,D,F

The lowest sublevel that can be found within an electron is called

the s sublevel

The maximum number of electrons that can go into the f sublevel is
 14
The quantum number

= the number of sublevels

Quantum mechanical model
determines the allowed energies an electron can have and how likely it is to find the electron in various locations around the nucleus
Atomic orbital
often thought of as a region of space in which there is a high probability of finding an electron  
Quantum
the amount of energy required needed to move an electron from one energy level to another
Energy levels
fixed energies that an electron can have

 

 

  Atomic mass

weighted average mass of the atomic atoms in a naturally occurring sample or element
Isotopes
atoms that have the same number of protons but different number of neutrons also have different saggy assed mass numbers
# of neutrons

mass # – atomic #