1. Chapter 12 – The Periodic Table
Section 2 – Grouping the Elements (pp

2. GROUPS 1 & 2 VERY REACTIVE METALS
Group 1 – The Alkali Metals
The most reactive metals
1 electron in outer energy level
Other shared properties – soft, silver colored; shiny; low density
Group 2 – The Alkaline Earth Metals
-very reactive, but less reactive than alkali metals
2 electrons in outer energy level
Other shared properties – silver colored; more dense than alkali metals

3. THE TRANSITION METALS Groups 3-12
1 or 2 electrons in outer energy level
Less reactive than alkaline earth metals
Lanthanides and actinides are included in this group
Other shared properties: shiny; good conductors of thermal energy and electric current; higher densities and melting points than elements in Groups 1 & 2

4. LANTHANIDES
They follow the element Lanthanum.
Shiny, reactive metals

5. ACTINIDES They follow the element Actinium
All are radioactive. This means they are unstable.
Elements listed after Plutonium (element 94) do not occur in nature. They are man made.

6. GROUP 13 Also known as the Boron Group
3 electrons in the outer energy level
Group contains Boron (a metalloid) and 4 metals (Al - aluminum, Ga - gallium, In - indium & Tl- thallium)
Reactive
Other shared properties: solid at room temperature

7. GROUP 14 Also known as the Carbon Group
4 electrons in outer energy level
Reactivity varies among the elements
Group contains 1 nonmetal (carbon), 2 metalloids (Si - silicon & Ge - Germanium) and 3 metals (Sn - tin, Pb - lead and Uuq)
Other shared properties: solid at room temperature

8. GROUP 15 Also known as the Nitrogen Group
Have 5 electrons in the outer energy level
Reactivity varies among the elements
Group contains 2 nonmetals (N - nitrogen & P - phosphorus), 2 metalloids (As- Arsenic & Sb - antimony) & 1 metal (Bi - bismuth)
Other shared properties: all but Nitrogen are solid at room temperature

9. GROUP 16 Also known as the Oxygen Group
Have 6 electrons in the outer energy level
Very reactive
Contains 3 nonmetals (O - oxygen, S - sulfur & Se - selenium), 1 metalloid (Te - tellurium) & 2 metals (Po - polonium & Uuh)
Other shared properties: all but Oxygen are solid at room temperature

10. GROUP 17 Also known as the Halogens
Group contains all nonmetals (F - fluorine, Cl - chlorine, Br - bromine, I – iodine & At - astatine)
Very reactive
There are 7 electrons in the outer energy level
Other shared properties: poor conductors of electric current; react violently with alkali metals to form salts; never found uncombined in nature.

11. GROUP 18 Also known as the Noble Gases
Group contains all nonmetals (He - helium, Ne - neon, Ar - argon, Kr - krypton, Xe - xenon, Rn – radon & Uuo)
There are 8 electrons in the outer energy level (He only has 2)
They are unreactive.
Other shared properties: colorless, odorless gases at room temperature

12. HYDROGEN Stands apart Only 1 electron in the outer energy level
Very reactive
Other properties: colorless, odorless gas at room temperature; low density; reacts explosively with oxygen.