HL Atomic Structure

Sketch the graph of first ionisation energies.What other evidence do we have for electron

sub levels ?http://www.ptable.com/

Aims

• Show how successive ionization energy data is related to the electron configuration of an atom.

Trends in the PT

Sub Levels Evidence

Further Evidence

Problem

• Predict which element in each of the following pairs has the larger first ionization energy.

• (a) Na or Mg

• (b) Mg or Al

• (b) B or Al

• (c) F or Cl

Definitions

• Aufbau– Lowest energy filled first

• Hund– Same sub-shell – singly first

• Pauli– no two electrons in the same atom can be in the

same quantum state

s p d f shapes

http://lincoln.pps.k12.or.us/lscheffler/OrbitalShapesOverheads.htm

Picturing Electrons

Filling Orbitals

• http://www.youtube.com/watch?v=fv-YeI4hcQ4&feature=fvw

Orbitals

• Rules :-– Electrons are found in orbitals– 2 electrons in each orbital – with opposite ‘spin’– They will pair up only when all empty orbitals are

filled.– S can hold 2– P can hold 6 ( px, py and pz )– D can hold 10 – F can hold 14

Order of Filling of Orbitals

Order of Filling of Orbitals

Blocks in the PT

How To ….

• Use the Periodic Table to find the atomic number, and hence number of electrons.

• Fill up orbitals in the order 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p - until you run out of electrons. The 3d is the awkward one - remember that specially. Fill p and d orbitals singly as far as possible before pairing electrons up.

Task

• Write a ‘how to fill electronic orbitals help sheet’

• Include 10 elements with their full electron configuration 3 from s block – 3 from p block and 4 from d block.

HL Atomic Theory

• Apply the Aufbau principle, Hund’s rule and the Pauli exclusion principle to write electron configurations for atoms and ions up to Z = 54.

What is electron configuration of

• Ca

• C

• Zn

• S

Cu and Cr Chromium and Copper have electron configurations [Ar] 3d5 4s1 and [Ar] 3d10 4s1 respectively

Ions Notation

Sc - (Ar) 4s2 3d1Ti - (Ar) 4s2 3d2V - (Ar) 4s2 3d3Cr - (Ar) 4s1 3d5Mn - (Ar) 4s2 3d5Fe - (Ar) 4s2 3d6Co - (Ar) 4s2 3d7Ni - (Ar) 4s2 3d8Cu - (Ar) 4s1 3d10Zn - (Ar) 4s2 3d10

Plenary

• Questions 58 - 60

Starter

Let’s Balloon