T1W4L2

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Electronic Configuration §

Sub-shells §

• Shells are divided into sub-shells
• Sub-shells are called s, p, d, f (dont need to know names sharp, principal, diffuse, fundamental)
  • ’s’ sub-shell: 2 electrons. (group 1-2)
  • ‘p’ sub-shell: 6 electrons. (group 13-18)
  • ‘d’ sub-shell: 10 electrons (group 3-12)
  • ‘f’ sub-shell: 14 electrons (bottom stuff)
• For principal quantum shells
  • n=1: 1s
  • n=2: 2s2p
  • n=3: 3s3p4s3d
  • n=4: 4s4p4d4f

Order of filling of sub-shells §

• The rule for filling sub-shells with electrons is to start with the lowest energy available sub-shell.
• The sub-shells can be seen below in increasing oder of energy.${}_{1}H=1s^1$
• 36 2, 8, 18, 8 $1s^{2}2s^2{p}^{6}3s^{2}3p^{6}4s^{2}3d^{10}4d^6$

Practice §

1. 11Na = 2, 8, 1 = 1s2, 2s2 2p6, 3s1
2. 16S = 2, 8, 6 = 1s2, 2s2 2p6, 3s2 3p4
3. 19K = 2, 8, 8, 1 = 1s2, 2s
4. 26Fe = 2, 8, 14, 2 = 1s2, 2s2 2p6, 3s2 3p6 3d6, 4s2
5. 36Kr = 2, 8, 18, 8 = = 1s2, 2s2 2p6, 3s2 3p6 3d10, 4s2 4p6
6. 33As3- = 36As = 2, 8, 18, 8 = 1s2, 2s2 2p6, 3s2 3p6 3d10, 4s2 4p6
7. 38Sr2+ = 36Sr = 2, 8, 18, 8 = 1s2, 2s2 2p6, 3s2 3p6 3d10, 4s2 4p6

• each subshell is made of orbitals
• an orbital is a region around the nucleus of an atom that can hold up to two electrons with opposite spins.
  • electrons have spin in opposite directions to stop repulsion.
  • s orbital is a sphere O
  • p orbital is like an 8
  • 2 electrons maximum, regardless of its orbital
  • d orbital is like a silly shape
  • 

How to put electrons in boxes §

n= 4 | _ _ _ _ __ | _ _ _

n = 3 |

n = 2 |

n = 1 |

idk watch this or smth to revise https://www.youtube.com/watch?v=JzmL6kktPRY&ab_channel=GradefruitAcademy (do we even need to know this? (no) )