1. Periodic Trends
Chemistry 2

2. Essential Question
How do the properties of elements repeat in periodic manner by virtue of their organization on the periodic table?

3. Periodicity Repeating trends in: Atomic Radius Ionization energy (IE)
Electronegativity

4. Atomic Radius
Distance from the center of the nucleus to the edge of the electron cloud

7. Ionic Radii Cations Anions Smaller than their parent atom
K vs. K+
Anions
Larger than their parent atom
O vs. O-2

8. Checkpoint List in order from smallest to largest atomic radii:
Ti, Na, F, Cu,

9. Ti, Na, F, Cu,

10. Ionization Energy Energy required to remove an electron
A + energy → A+ + e-

12. Ionization Energy Factors affecting:
Valence electrons in the outer shell
The closer to 8 electrons, the harder to remove
The number of energy levels
The closer to the nucleus the energy level is, the harder it is to remove.

13. Ionization Energy Trend: IE decreases down a group
IE increases L to R across a period

14. Checkpoint #2 Place these elements in order from lowest to highest IE:
Mn, Cs, Cl, F

15. Mn, Cs, Cl, F

16. Electronegativity
The ability of an atom to attract electrons in a bond

18. Electronegativity Trend: Most Electronegative – Fluorine
Increases up a group
Increases L to R across a period
Most Electronegative – Fluorine
Least – Francium

19. Electronegativity

20. Checkpoint #3 Place in order from high to low electronegativity:
N, Mg, Fe, F, Pt, Sr