Electron configuration.pptx for GCE/ IAL

Electronic configuration for grade 12 - GCE/IAL

1. ELECTRON CONFIGURATION ELECTRON CONFIGURATION STARTER What are quantum numbers? Name the orbitals you have studied Pair discussion Shapes of orbitals VOCABULARY Electron configuration Pauli exclusion principle Aufbau principle Hund’s rule valence electrons

2. Learning objectives Students are expected to: - explain the differences between aufbau principle, Pauli exclusion principle, and Hund’s rule – understand and write electronic configurations using orbital diagrams, complete electron configuration notation, noblegas notation, and valence electron-dot structure

3. The arrangement of electrons in an atom is called the atom’s electron configuration The three principles; The Aufbau principle The Pauli exclusion principle Hund’s rule Define how the electrons can be arranged in an atom’s orbital Discussion

4. The Aufbau principle It states that each electron occupies the lowest level energy orbital available position of the 3d orbitals are shown at a slightly higher level than the 4s - and so it is the 4s orbital which will fill first, followed by all the 3d orbitals and then the 4p orbitals Teacher’s talk

5. The  Pauli Exclusion Principle   states that, in an atom or molecule, no two electrons can have the same four electronic quantum numbers. As an orbital can contain a maximum of only two electrons, the two electrons must have opposing spins . Teacher’s explanation

6. C 6 Hund's rule   states that: Every orbital in a sublevel is singly occupied before any orbital is doubly occupied. All of the electrons in singly occupied orbitals have the same spin (to maximize total spin).

7. Group activity Draw the orbitals for oxygen

8. Electronic configuration and orbital diagram for elements

9. What is noble gas notation? A  noble gas  configuration of an atom consists of the elemental symbol of the last  noble gas  prior to that atom, followed by the configuration of the remaining electrons. So for sodium, we make the substitution of [Ne] for1s 2 2s 2 2p 6 part of the configuration. Sodium's  noble gas  configuration becomes [Ne]3s1 Teacher’s talk

10. ACTIVITY Write the electronic configuration for the following elements Using noble gas notation K P Cl S Al Aluminium Potassium Chlorine

11. Definition  of  valence electron ;- a single  electron  or one of two or more  electrons  in the outer shell of an atom that is responsible for the chemical properties of the atom. activity How many valence electrons are present in the following elements ? K Ca N F C

12. ELECTRON –DOT STRUCTURE Electron dot diagram or a Lewis diagram or a Lewis structure) is a representation of the valence electrons of an atom that uses dots around the symbol of the element. The number of dots equals the number of valence electrons in the atom . These dots are arranged to the right and left and above and below the symbol, with no more than two dots on a side. (It does not matter what order the positions are used.) For example, the Lewis electron dot diagram for calcium is simply