1. Periodic trends re-teach
Ionic Radii

2. Why? Majority answered incorrectly. Reteach necessary
Quiz will be given after presentation
Points added back on to test grade
Test grades will be entered later today

3. What is a radius?

4. What is an ion? An ion is a charged atom.
Remember: Electrons have a negative charge!!!!
A cation is a positive ion that has lost electron(s)
An anion is a negative ion that has gained electron(s)

5. Important Trends
Ionic Radii- distance from the nucleus to the outermost electron in an ion

6. Ionic Radius: WHAT IS THE TREND?
Increases moving down a family
Due to an increase in energy levels

7. Ionic Radius: WHAT IS THE TREND?
Varies as you go across a period from right to left
This is because as you go across a period, atoms switch from cations to anions.

9. Ionic Radius
Varies
Increases

10. Ionic radius: Why does this trend occur?
Increases Going Down a Group Due to: an increase in energy levels Varies Going Across a Period Due to: switching from cations to anions

11. When comparing two ions:
Ask yourself, “What Noble Gas does it become?
The noble gas further down the periodic table has the larger ionic radius
The noble gas further up the periodic table has the smaller ionic radius.

12. Practice Which element has the larger ionic radius?
Step 1: Write the noble gas they become
Cl1- ____ or Br1- ____
Step 2: Which noble gas is lower on the periodic table?
Step 3: Select the ion that goes with the noble gas chosen in step 2.

13. Practice: Larger ionic radius
O2- ____ or Ca2+____ B3+ ____ or S2- _____

14. Practice Which element has the smaller ionic radius?
Step 1: Write the noble gas they become
F1- ____ or Li1+____
Step 2: Which noble gas is higher on the periodic table?
Step 3: Select the ion that goes with the noble gas chosen in step 2.

15. Practice: smaller ionic radius
S2- ____ or Al3+____ Fr1- ____ or Te2-_____

16. Quiz time! Clear desk for quiz You only need a writing utensil
Periodic table will be provided