1. Trends
of the
Periodic Table

2. Trends
Trends result from the tug of war between two major forces within the atoms
Electron Shielding – the repulsive force caused by electrons ( an electron closer to the nucleus shields electrons further away from the nucleus from feeling the attraction of the nucleus.)
Nuclear Attraction – the attraction of negative electrons for the positive nucleus

3. Triplet Trends Organize trends into triplets
Use only increasing properties
Learn the diagonal NOT the two vectors that make up the diagonal…..
You can always recreate the two vectors so you have less to learn or memorize
Learn the members of each triplet and what the increasing diagonal does

4. Triplet 1: Driven by increasing protons
     Atomic Number m
     Atomic Mass
     Nuclear Charge

5. Atomic Number
Increases to the right
Increases down

6. Atomic Mass
Increases to the right
Increases down

7. Nuclear Charge
Increases to the right
Increases down

8. Triplet 2: Driven by increasing electron to electron shielding or repulsion
     Atomic Radii Size
   Distance between covalent nuclei l
     Ionic Radii Size
     Overall Activity
    

9. Atomic Radius
Is taken as the covalent radius for non-metallic elements and as the metallic radius for metals

10. Atomic Radius
Covalent radius is one-half the distance between the nuclei of two identical atoms that are singly bonded to one another.

11. Atomic Radius
Covalent radii for elements whose atoms do not bond to one another can be estimated by combining radii of those that do with the distances between unlike atoms in various molecules.

12. Atomic Radius
Metallic radius is one-half the closest internuclear distance in a metallic crystal.

13. Atomic Radius

14. Atomic Radius

15. Ionic Radii Size

16. Overall Activity

17. Triplet 3: Driven by nuclear attraction for electrons
     Ionization Energy
Energy required to remove an e- from element in its gaseous form k
     Electron Affinity
Change in charge when e- captured
     Electronegativity
Ability to bond & desire for e-

18. Ionization Energy
Is the energy required to remove the outermost electron from an atom or a positive ion in the ground state.

19. First Ionization Energy
Energy required to remove the first electron from a neutral atom.

20. First Ionization Energy

21. First Ionization Energy

22. First Ionization Energy

23. Second Ionization Energy
Energy needed to remove the outermost electron from a +1 ion.
Energy needed to remove the second electron from a neutral atom.

24. Second Ionization Energy

25. Electron Affinity
Energy released or absorbed when an electron is added to the valence level of a gas-phase atom.

26. Electron Affinity

27. Electron Affinity

29. Electronegativity
Ability to bond & desire for electrons