Follow the Rules
Every orbital in a subshell is singly occupied with one electron before any orbital is doubly occupied, and all singly occupied orbitals contain electrons with parallel spins
Hunds Rule
Be
Beryllium
Group 1A
Alkali Metals
1s22s22p1
B
Ductile, Malleable, and Conducts Electricity
metal
No two electrons in an atom may have the exact same set of quantum numbers.
Pauli Exclusion Principle
Titanium
Ti
Group 7A
Halogens
Cation with electron configuration:
1s22s22p6
Na+, Mg2+, Al3+
B, Si, Ge, As, Sb, Te, At, Ts
Metalloid
You cannot know both the energy and the position of an electron with absolute certainty.
Heisenberg Uncertainty Principle
Arsenic
As
Group 8A
Noble Gases
[Kr]5s14d5
Elements in Groups 1A and 2A
s-block elements
Electrons fill orbitals from lowest energy to highest energy.
Aufbau Principle
Na
Sodium
O, S, Se
Chalcogens
Diamagnetic element
Any full subshell example
Elements in Groups 3B-2B (3-12)
Transition Metals or d-block elements
The maximum number of electrons that may occupy any orbital.
Br
Bromine
Be, Mg, Ca, Sr, Ba, Ra
Alkaline Earth Metals
At
[Xe]6s24f145d106p5
Lanthanides and Actinides
f-block elements