1. Chemical Periodicity

2. Classifying by e- Configuration
Noble Gases – Elements in which the outermost s and p sublevels are filled
Representative Elements – Outermost s or p sublevel is only partially filled
Transition Metals – Metallic elements in which the outermost s and p sublevel contain electrons
Inner Transition Metals – Metallic elements in which the outermost s and nearby f sublevel generally contain electrons

3. Trends in Atomic Size
Group Trends – Atomic size generally increases as you move down a group
Electrons are added to the next higher energy level as you move down
Periodic Trends – Atomic size generally decreases as you move left to right across a period
More protons pull the outermost electrons closer

5. Trends in Ionization Energy
Group Trends – Ionization energy decreases as you move down a group
The outermost electron is farther from the nucleus and easier to take
Periodic Trends – Ionization energy increases as you move left to right across a period
Greater attraction of the nucleus

7. Trends in Ionic Size
Group Trends - Positive ions are always smaller than the neutral atoms from which they form (loss of outer shell electrons)
Negative ions are always larger than the neutral atoms (gain of electrons and less attraction)
Periodic Trends – size increases from left to right

8. e- F- F e-
Li+ Li
Cl- e- Cl e-
Na+ Na

9. Trends in Electronegativity
The electronegativity of an element is the tendency for the atoms to attract electrons when they are chemically combined with atoms of another element
Group Trends – electronegativity decreases moving down the group
Periodic Trends – electronegativity increases moving left to right across a period

11. A R D
I E I A R I I E D I S E D
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