1. Props. in a group are similar because the atoms have the same # of electrons in their outer energy levels Atoms will take, give or share electrons with each other in order to have a complete set of electrons Elements that undergo this process are called reactive

2.  Contains metals  1 electron in the outer level  Soft enough to cut with a knife  Silver color, shiny, low density  Very reactive, react with water to form hydrogen gas  Most reactive metals because they can easily give away the one outer shell electron  So reactive that in nature they are found only combined with other elements  Cmpds. formed from them are very useful  Ex.-Sodium Cholride-Table salt, Potassium Bromide- Used in photography

3. 2 electrons in outer level Very reactive, but less reactive than alkali metals More difficult for atoms to give 2 electrons than 1 when joining with other atoms Other properties: Silver color, higher densities than alkali metals

4.  1 or 2 electrons in the outer level  Less reactive than alkaline-earth metals  Other properties: Shininess, good conductors of thermal energy and electric current, higher densities and MP than elements in Groups 1 and 2 (except mercury-liquid @ room temp.)  Many are silver-not all-Gold is an example  Some are reactive and some are not that reactive  Lanthanides & Actinides:placed below the table so the table is not so wide  Lanthanides:shiny, reactive metals.  Actinides:radioactive(unstable)  Elements after 94 are made in labs

5. This group contains one metalloid and four metals 3 electrons in the outer level They are reactive They are solid at room temp. Most common element is Aluminum-most metal found in the Earth’s crust

6. Contains 1 nonmetal, 2 metalloids and 2 metals Contains 1 nonmetal, 2 metalloids and 2 metals 4 electrons in the outer level 4 electrons in the outer level The reactivity varies among the elements The reactivity varies among the elements Solid at room temperature Solid at room temperature Example of a nonmetal in the Carbon group: Diamonds: hardest material known. Soot: formed from burning oil, coal and wood. Example of a nonmetal in the Carbon group: Diamonds: hardest material known. Soot: formed from burning oil, coal and wood. Both are natural forms of Carbon Both are natural forms of Carbon

7. Contains 2 nonmetals, 2 metalloids and 1 metal Contains 2 nonmetals, 2 metalloids and 1 metal 5 electrons in the outer level 5 electrons in the outer level Reactivity varies among the elements Reactivity varies among the elements Solid at room temp. except for nitrogen (it is a gas) 80% of the air you breathe Solid at room temp. except for nitrogen (it is a gas) 80% of the air you breathe Nitrogen-not very reactive but Phosphorous is extremely reactive (striking a match) Nitrogen-not very reactive but Phosphorous is extremely reactive (striking a match)

8. Contains 3 nonmetals, 1 metalloid, and 1 metal 6 electrons in the outer level These elements are reactive All but oxygen are solid at room temp. Oxygen makes up about 20% of the air you breathe.

9. Contains nonmetals Contains nonmetals 7 electrons in the outer level 7 electrons in the outer level Very reactive because their atoms only need to gain only 1 electron to have a complete outer level Very reactive because their atoms only need to gain only 1 electron to have a complete outer level Poor conductors of electric current, violent reactions with alkali metals to form salts, never in uncombined forms in nature Poor conductors of electric current, violent reactions with alkali metals to form salts, never in uncombined forms in nature

10. Contains nonmetals Contains nonmetals 8 electrons in the outer level (except helium which has 2) 8 electrons in the outer level (except helium which has 2) Unreactive elements-full set of electrons in their outer level Unreactive elements-full set of electrons in their outer level Colorless, odorless gases at room temp. Colorless, odorless gases at room temp. These are useful gases-argon: lightbulbs, helium: makes blimps and weather balloons float These are useful gases-argon: lightbulbs, helium: makes blimps and weather balloons float

11.  1 electron in the outer level  Hydrogen is reactive  Properties of H do not match any other group so it is set apart.  Colorless, odorless gas at room temp., low density, explosive reaction with oxygen  Can give away one electron when they join with other atoms.  Physical props. of hydrogen are more like nonmetals than metals.  Hydrogen is found in stars. Most abundant element in the universe.  Useful in rocket fuel because it is so reactive