Energy levels, sub-levels and orbitals Flashcards
Formula for maximum number of electrons an energy level can hold
2n^2
Max no. of electons in s sub-level
2
Max number of electrons in p sub-level
6
Max number of electrons in d sub-level
10
Max number of electrons in f sub-level
14
What are the two elements that are exceptions in electron configurations?
Chromium and copper
Electron configuration for chromium
[Ar] 4s¹ 3d⁵
Electron configuration for copper
[Ar] 4s¹ 3d¹⁰
What does an element’s block on the periodic table (s,p,d or f) tell us about its valence electrons
Elements in a particular block have their valence electrons in the sub-level indicated by the block
No. of orbitals in s sub-level
1
No. of orbitals in p sub-level
3
No of orbitals in d sub-level
5
No. of orbitals in f sub-level
7
Aufbau principle
In an atom or ions groud state, electrons fill up the lowest energy sub-levels before filling up higher energy sub-levels
Hund’s rule
In a sub-level, every orbital must be singly occupied with one electron before any can be doubly occupied with two electrons.
All electrons in singly occupied orbitals have the same spin
