1. Bell Work 11/3/15 Sit with your assigned group
Power up laptop and go to class website
Read over the Periodic Trends Packet

2. Goals for Today Research property
Discover and explain the periodic trend.
Create a poster.
Share your findings with two groups (answer questions 1 through 7)
Groups 1,2,3 will share with each other
Groups 4,5,6 will share with each other

3. Your Grade for Today Actively support your group
Every student contributes to presentation
Poster contains the following items
Your group’s names and class period
Identify Trend
Element Symbols and values in the squares
Units for property specified
Arrow on the side showing increasing trend
Arrow on the top showing increasing trend
(See example at the front)

4. Bell work 11/5/15 Sit with your group Spend 5 minutes discussing:
Format of your presentation
Determine who will say what
Name of property you researched
Definition of property
Answer questions 1-7
Horizontal trend
Direction of arrow
Vertical trend
Highest
Lowest
Why this trend occurs (both horizontal and vertical)

5. Periodic Trends Summary Notes
Periodic table unit
Periodic Trends
Summary Notes

6. Important Trends
Electronegativity- ability of an atom to attract electrons and form a chemical bond
Increases moving up the group
Increases left to right across a period
Noble Gas family has 0 electronegativity

7. Electronegativity
Increases
Increases

8. Why does this trend exist?
Going down a family, the _____________ increase. The positively charged ________ of smaller elements with fewer energy levels can more easily ________ electrons. Going across a period, valence electrons __________ and the atom gets closer to achieving an ______. Thus, the elements on the right side more easily _______ electrons. The noble gases have ____ electronegativity because they already have __ electrons (full octet).

9. Practice Which element is more electronegative? F or Be Sn or Si
Ni or Cr
Cs or Br

10. Important trends
Ionization Energy- the energy needed to remove an electron
Creates an ion
The number of protons and electrons are no longer equal.
Increases moving up the group
Increases left to right across a period

11. Ionization energy
Increases
Increases

12. Why does this trend exist?
Going down a family, the _____________ increase. The positively charged ________ is farther away from the __________ electrons. Thus, it take less ________ to remove an electron. As you go across a period, the number of valence electrons ________, with elements on the right side closer to having an ______. The energy required to remove an electron from potassium (with ___ valence electron) is _____ than the energy to remove an electron from bromine (which has ______ valence electrons).

13. Practice Circle the element that has the greater ionization energy
Zr or Sn
S or Cl
Cs or Ba
C or Ne

14. Important periodic Trends
Atomic Radii- distance from the nucleus to the outermost stable electron
Trend:
Increases moving down the groups
Decreases right to left across the periods

15. Atomic Radius

16. Why does this trend exist?
As you go down a family, there are more _____________. More ____________ leads to an atom with a larger _____. The valence electrons of all elements in a period are in the same ___________. As you go across a period, one more _______ is added. That one extra ____________ charged proton pulls the electrons in a little ______ making the radius a bit _________ across the period.

17. Atomic Radius
Increases
Increases

18. Practice Which element has the larger atomic radius? Fe or Ni F or N
Ne or Br
C or F

19. Important Trends
Ionic Radii- distance from the nucleus to the outermost electron in an ion
Increases moving down a family
As you go across a period from right to left, the trend varies.
Ask yourself, “What Noble Gas does it become?
The noble gas further down the periodic table has the higher ionic radius

20. Why does this trend occur?
As you go down a family, there are more ____________. More __________ leads to an atom with a larger _____. As you go across a period, the ionic radius can ____. To compare two ____ in the same period, determine which _________ they will become. The ion which becomes a noble gas further ____ the periodic table would have the ______ ionic radius.

22. Practice Which element has the larger ionic radius? Cl- or Br-
O2- or Ca2+
B3+ or S2-
K+, Ca 2+, Ga3+

23. Summary
Which properties trend in the same way?