1. Periodic table
Chapter 6

2. Order
The periodic table is arranged in order of increasing atomic number
Identifies the element
Gives the number of protons
Gives the number of electrons in a neutral atom

3. Properties
The properties within a period change as you move from left to right
Elements within a group have similar physical and chemical properities
Example the Alkali Metals:
Highly reactive in water
Each element has one electron in its valence shell
Soft metals with low melting and low boiling points
Produce colored flames when burned

4. Metals nonmetals and metalloids
Across a period the properties of elements become less metallic and more non metallic
Metals- good conductors of heat and electric current
80% of the elements are metal

5. Metalloids- stair step line
Properties similar to those of metals and non metals

6. Non metals- upper right corner of periodic table (exception on Hydrogen)
Gases at room temperature
Poor conductors
Brittle

7. Groups of the Periodic Table

8. Valence electrons
Electrons found in the outermost energy level of the atom.

9. Ions - atoms with different a number of electrons then protons
Cation- positive charge
Anion- negative charge

11. Reading the periodic table
Alkali metals- 1A
Also tells you it has 1 electron in its valence shell
When they are an ion they are a cation with a +1 charge (it wants to give one electron away)
Alkali earth metals – 2A
Also tells you it has 2 electrons in its valence shell
When they are an ion they are a cation with a +2 charge
Group – 3A
+3 charge

12. Reading the periodic table
Halogens – 7A
Also tells you it has 7 electrons in its valence shell
Salts when bonded to a metal
When it’s a anion it has a -1 charge (it wants one electron)
Nobel gases –8A
Valence shell is full – VERY STABLE
Transition metals
In d orbital
Ag+1 Zn+2

13. Trends Shielding Effect
Electrons in energy levels closer to the nucleus “shield” the valence electrons from the pull of the positively charged nucleus.

14. Atomic Radius
Atomic radius increase from top to bottom
Decreases from left to right
Shielding effect increases as radius increases

15. Ionization energy
Energy required to remove an electron from an atom
Increase from bottom to top
Increase fro left to right

16. Atomic Radius in ions

17. Electronegativity
Ability to attract electrons when the atom is in a compound
Fluorine has the highest electronegativity