Electron Configuration

Question 1

If you add up the superscripts in an elements electron configuration, it should add to?

Answer 1

the elements atomic #, or total number of e- in that element

Question 2

What is weird about row 4 while naming electron configurations?

Answer 2

Even though the first D block element is in row 4, it reverts backwards by 1 number as 3D (NOT 4D)

Question 3

What is weird about row 6 while naming electron configurations?

Answer 3

Even though the first F block element is in row 6, it reverts backwards by 2 numbers as 4F (NOT 6F)

Question 4

Hund’s Rule

Answer 4

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

Question 5

What is “condensed electron configuration”?

Answer 5

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

Question 6

valence electrons

Answer 6

are the e- in an atoms outermost shell. The vast majority of chemical reactions involve the exchange or sharing of outer e- aka valence

Question 7

core electrons

Answer 7

are the e- that are buried inside the inner shells of an atom. Not typically used in chemical reactions

Question 8

when looking at an electron configuration, which ones are the valence e-?

Answer 8

the e- with the largest principle quantum number (n), these are the highest energy e-

Question 9

when looking at an electron configuration, which ones are the core e-?

Answer 9

all electrons that are NOT with the largest principle quantum number

Question 10

What is the exception to finding/counting valence e- in electron configurations? (We typically only count those with highest principle (n) number)

Answer 10

All e- in the d-block/shell are also valence electrons.

Question 11

principle quantum number (n) is directly related to?

Answer 11

distance from nucleus, energy, and reactivity

Question 12

What 3 things also increase as n (principle quantum number) increases?

Answer 12

1) distance from nucleus
2) energy
3) reactivity

Question 13

Aufbau Principle about lower energy orbitals?

Answer 13

e- fill the lowest energy orbitals first

Question 14

Pauli Exclusion Principle

Answer 14

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

Question 15

What are the 5 electron configuration exceptions?

Answer 15

Cr, Mo, Cu, Ag, Au

Question 16

Benefit of Cr and Mo having e- configuration expression exceptions?

Answer 16

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)

Question 17

Benefit Cu, Ag, and Au having e- configuration expression exceptions?

Answer 17

bring down higher energy paired s e- just to get the benefit of having it in a lower energy state, more stable

Question 18

ground state electron configuration?

Answer 18

the way e- are typically arranged when nothing “exciting” is going on

Question 19

excited state electron configuration?

Answer 19

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.

Question 20

What happens when an e- relaxes from excited state and goes “back down” to ground state?

Answer 20

It gives off energy in the form of heat, color, or light (or a combination). This is how light bulbs work

Question 21

what happens when an e- absorbs a photon?

Answer 21

It can be promoted to a higher energy shell or orbital.