1. WHAT ARE PERIODIC TRENDS?

2. WHAT HAPPENS TO ATOMIC RADII?
Does a negative ion (anion) get larger or smaller?
Does a positive ion (cation) get larger or smaller?

3. WHAT IS IONIZATION ENERGY?
The energy required to remove an electron
Which element has the highest ionization energy? Why?

4. WHAT IS ELECTRONEGATIVITY?
The ability of an atom to pull off an electron.
Which element has the highest electronegativity? Why?

5. WHAT HAPPENS TO REACTIVITY?
What happens to reactivity in the Alkali Metals?
What happens to reactivity in the Halogens?

6. How do we balance equations?
Law of Conservation of Mass: No matter can be created or destroyed.
Begin by counting all the atoms on each side of the yield sign (→)
Now it’s trial and error but there are some guidelines that help you get started:
Begin by balancing the elements that are combined and that appear only once on each side of the equation.
Balance polyatomic ions as single units
Balance H atoms and O atoms after all other elements have been balanced
Try not to change large compounds

7. LET’S BALANCE THIS EQUATION!
CO2 + H2O → C6H12O6 + O2
How many atoms on each side?
Which element do you begin with?
Remember you cannot change subscript, only add coefficients!
6CO H2O → C6H12O6 + 6O2

8. How Will Chemicals React?
H2 + O2 → H2O
REACTANTS → PRODUCTS
EXOTHERMIC REACTIONS: Heat is a product (feels hot!)
ENDOTHERMIC REACTION: Heat is a reactant (feels cold!)

9. Which type of reaction is this?

10. WHAT ARE THE TYPES OF REACTIONS?
SYNTHESIS
DECOMPOSITION
SINGLE DISPLACEMENT
DOUBLE DISPLACEMENT
COMBUSTION
A + X → AX
AX → A + X
A + BX → B + AX
AX + BY→ AY + BX
A + O2 → CO2 + H2O

11. WHAT IS AN ACTIVITY SERIES?
An activity series is a list of elements organized according to their reactivity
The most active element is placed on top and can replace any other element below it