1. Learning Goals Understand the periodic trends
Be able to explain these three trends: atomic size, ionization energy and electronegativities

2. Periodic Trends

3. Valence Electrons
 Outermost electrons of an atom

6. Sodium vs Chlorine

7. Sodium vs Chlorine
These elements are both in the same row/period. Because of that, you are adding electrons to the same energy level. More protons and more electrons  ______________ NUCLEAR PULL  The pull between the negative outer electrons (valence) and the positive makes the atom slightly _______________than it would have been!
STRONGER
SMALLER

8. remove opposite higher
Ionization Energy
Ionization energy is the energy required to _______________ the outermost electron in an atom.
The overall trends in ionization energy are _________________ to those for atomic radius.
The more tightly electrons are held, the ________________ the ionization energy, and the smaller the atom or ion size.
remove
opposite
higher

9. Potassium vs Lithium
Bigger Atomic Size?
Higher Ionization Energy?

10. chemical Electronegativity
Electronegativity is a relative value which compares how much an atom attracts and holds e-’s in a ____________ bond.
Electronegativites INCREASE from the lower left to upper right. As you get closer to Fluorine (which is the highest!!)
chemical

11. Overall General Trends
Electronegativity

12. Sample Problems
Which atom has a bigger atomic radius: Bromine or Germanium Which atom has a higher ionization energy: Magnesium or Radium

13. Exit Slip Iodine or Fluorine Chlorine or Aluminum
1) Which atom is bigger (bigger atomic radius):
Iodine or Fluorine
2) Which atom has a higher ionization energy:
Chlorine or Aluminum