electronic configuration

Question 1

what is a shell

Answer 1

a ​group of atomic orbitals​ same value of the principal quantum number

Question 2

what is a subshell

Answer 2

all the orbitals of the same type within a shell

Question 3

what is an orbital

Answer 3

region of space around nucleus (high probability of finding electron)
holds 2 electrons (opposite spins)

Question 4

Hund’s rule

Answer 4

Fill each orbital with one electron before pairing them up
(Cr and Cu exceptions as d5/d10 more stable that 4s2)

Question 5

Shell order v/ filling order

Answer 5

Electron config should show shell order (3d before 4s) even though they fill in the opposite order)

Question 6

formula for total no. of electrons in a shell

Answer 6

2(n)^2
n = shell number

Question 7

3d / 4s relative energies

Answer 7

4s filled first (lower energy)
once filled, 4s has more energy than 3d
4s empties first