1. The Periodic Table

2. Group vs. Period Group- column
Similar chemical and physical properties (react similarly)
Period- row
Number of shells

3. Let’s Label the Table

4. Groups ~ Families
Alkali metals (1)- react with water to from an alkaline solution
Alkali earth metals (2)- reactive, but not as reactive as Group 1
Transition metals (middle)- valence electrons are present in more than one shell

5. More Groups ~ Families Chalcogens (6)- found in copper ore
Halogens (7)- are very reactive; only one electron to fill outer shell
Noble gases (8)- almost non-reactive because have completely filled outer shells

6. Metals Usually solids at room temperature Properties:
electrical conductors
have luster
malleable

7. Non-metals Elements in the upper right corner of the periodic table.
Properties:
generally brittle
non-lustrous
poor conductors of heat and electricity
can be gases, brittle solids, liquid

8. Metalloids
Elements that lie on a diagonal line between the metals and non-metals.
Their chemical and physical properties are intermediate between the metals and non- metals

9. Periodic Table Trends

10. Atomic Radius Definition: measure of the size of atoms
the distance from the nucleus to the edge of the electron cloud (shell)

11. Atomic Radius- Trends
How does atomic radius change as you go down a group? –bigger (increases)
Why?- more electrons
How does atomic radius change as you go across a period? - smaller (decreases)
Why?- radius contracts as charge increases Na Mg Al Si P S Cl Ar

12. Ionization Energy
Definition: amount of energy required to completely remove an electron (from a gaseous atom)
1st ionization energy- energy required to remove 1st electron
2nd ionization energy – energy required to remove 2nd electron; greater than first
3rd ionization energy – energy required to remove 3rd electron; greater than first or second

13. Ionization Energy- Trends
Li+1
Ca+1
K+1
Rb+1
Cs+1
How does ionization energy change as you go up a group? - increases
Why?- electron is further away from the attraction of the nucleus
How does ionization energy change as you go across a period? - increases
Why?- nuclear charge is increasing

14. Electronegativity
Definition: the tendency for an atom to attract electrons to itself when it is chemically combined with another element

15. Electronegativity- Trends
How does electronegativity change as you go down a group? - decreases
Why?- bonding pair of electrons moves farther away from nucleus-> more willing to share
How does electronegativity change as you go across a period? - increases
Why?- charge increases -> more attraction
Non-metals want electrons (these are on the right side of the table)

16. Overview- Trends… Electronegativity Atomic Radius Ionization Energy
Arrows show direction of increasing
Atomic Radius
Ionization Energy

17. Practice~ Atomic Radius
Circle the atom that has the LARGER atomic radius
Li or O
K or Na

18. Practice~ Ionization Energy
Circle the particle in each pairs has the LOWER ionization energy
Al or B
Mg or Na

19. Practice~ Electronegativity
Circle the atom in each pair with the HIGHER electronegativity.
O or S
Li or F