Electron Configuration Flashcards
If you add up the superscripts in an elements electron configuration, it should add to?
the elements atomic #, or total number of e- in that element
What is weird about row 4 while naming electron configurations?
Even though the first D block element is in row 4, it reverts backwards by 1 number as 3D (NOT 4D)
What is weird about row 6 while naming electron configurations?
Even though the first F block element is in row 6, it reverts backwards by 2 numbers as 4F (NOT 6F)
Hund’s Rule
e- won’t pair up to occupy the same orbital until there’s no other option. e- will fill up orbitals one at a time
What is “condensed electron configuration”?
You have the same process as regular electron configuration BUT you start by writing, in brackets, the elemental symbol of the noble gas that comes just BEFORE the element in question. You will write the elemental configuration that comes after this noble gas but not before the noble gas. Less to write
valence electrons
are the e- in an atoms outermost shell. The vast majority of chemical reactions involve the exchange or sharing of outer e- aka valence
core electrons
are the e- that are buried inside the inner shells of an atom. Not typically used in chemical reactions
when looking at an electron configuration, which ones are the valence e-?
the e- with the largest principle quantum number (n), these are the highest energy e-
when looking at an electron configuration, which ones are the core e-?
all electrons that are NOT with the largest principle quantum number
What is the exception to finding/counting valence e- in electron configurations? (We typically only count those with highest principle (n) number)
All e- in the d-block/shell are also valence electrons.
principle quantum number (n) is directly related to?
distance from nucleus, energy, and reactivity
What 3 things also increase as n (principle quantum number) increases?
1) distance from nucleus
2) energy
3) reactivity
Aufbau Principle about lower energy orbitals?
e- fill the lowest energy orbitals first
Pauli Exclusion Principle
no two e- in the same atom can have the same 4 quantum numbers. In other words, no two e- in the same atom can have the exact same address
What are the 5 electron configuration exceptions?
Cr, Mo, Cu, Ag, Au
Benefit of Cr and Mo having e- configuration expression exceptions?
bring down higher energy S orbital e- into lower energy d orbital to get ALL of the e- unpaired (or 1 e- in each orbital)
Benefit Cu, Ag, and Au having e- configuration expression exceptions?
bring down higher energy paired s e- just to get the benefit of having it in a lower energy state, more stable
ground state electron configuration?
the way e- are typically arranged when nothing “exciting” is going on
excited state electron configuration?
when a photon or some form of energy hits an e-, the electron gets excited or “promoted” up to a higher energy orbital, this would change its typical ground state e- configuration.
What happens when an e- relaxes from excited state and goes “back down” to ground state?
It gives off energy in the form of heat, color, or light (or a combination). This is how light bulbs work
what happens when an e- absorbs a photon?
It can be promoted to a higher energy shell or orbital.
