Grouping the Elements

A sample squareBrainPOPPeriodic Table

Grouping the Elements

• The elements in a family or group in the periodic table often, but not always, share similar properties.

• The properties are the same because the elements have the same number of electrons in their outer energy level.

Reactive elements

• Atoms in these elements take, give, or share electrons with other atoms in order to fill the outer valence shell. They do this to form a compound with another element.

Hydrogen

• Electrons in outer level: 1• Don’t match the properties of any groups• Hydrogen belongs to a family of its own.• Most abundant element in the universe• Hydrogen is a diatomic, reactive gas.• Hydrogen reacts violently with oxygen. The hot water vapor that

forms as a result pushed the space shuttle into orbit.• Placed above the group 1 elements because it has only 1 electron

in it’s valance shell and can give one away• Properties are more like atoms of alkali metals• Hydrogen was involved in the explosion of the Hindenberg.• Hydrogen is promising as an alternative fuel source for cars

Group 1: Alkali Metals

• Electrons in outer level: 1• 1st column on the periodic table (Group 1) not including

hydrogen. • Most often found in compounds• Soft, silver-colored, shiny, low density• are soft enough to be cut with a knife • the densities of some elements are less than water• Most reactive of the metals• easily give away the single electron from the valence shell• React violently with water (Stored in oil to prevent reacting

with water and oxygen in the atmosphere)

Group 2: Alkaline-earth Metals

• Electrons in outer level: 2• Second column on the periodic table. (Group 2)• Still reactive but not as reactive as Group 1

because they have 2 electrons to give away in the valence shell

• Typically found in compounds such as calcium in chalk, plaster, cement, and of course, humans!

Groups 3-12: Transition Metals

• Properties vary widely • The atoms of the transition metals do not give away their

electrons as easily as in Groups 1 and 2 so they are less reactive.

• Properties: shiny, good conductors of thermal energy and electric current, higher densities and melting points

Transition Metals

(yellow)

Lanthanides and Actinides

• These bottom two rows from Periods 6 and 7on the periodic table are placed at the bottom to keep the table from being too wide

Lanthanides

Actinides

Lanthanides

• Named lanthanides because they follow the element lanthanum

• Shiny, reactive metals• Some are used to make different types of steel

Lanthanides

Actinides

• Actinides follow the element actinium• All are radioactive, which means they are unstable• Atoms from a radioactive element can change into

atoms of a different element• Elements after plutonium (94) do not occur in nature

Actinides

Group 13: Boron Group

• Electrons in outer level: 3• Group contains 1 metalloid and 4 metals• Reactive• Solid at room temperature• Most common element is Al (aluminum)• Al is most abundant metal in Earth’s crust• 1880’s Al more valuable than gold

Group 14: Carbon Group

• Electrons in outer level: 4• Group contains 1 nonmetal, 2 metalloids, and 2 metals• Reactivity varies among the elements• Solid at room temp• 2 metalloids in this group make computer chips• Diamonds and soot are both natural forms of carbon!

Group 15: Nitrogen Group

• Electrons in outer level: 5• Group contains 2 nonmetals, 2 metalloids, and 1 metal• Reactivity varies among the elements• All but nitrogen are solid at room temperature; nitrogen

is a gas at room temp• Nitrogen non reactive, phosphorous extremely reactive

and only found combined with other elements in nature

Group 16: Oxygen Group

• Electrons in outer level: 6• Group contains 3 nonmetals, 1 metalloid, and 1

metal.• All but oxygen are solid at room temperature• Many things that stink, contain sulfur (rotten

eggs, garlic, skunks,etc.) • Reactive

Groups 17 and 18:Nonmetals Only

• Group 17: Most reactive nonmetals• Group 18: Least reactive nonmetals; normally

won’t react with other elements

Group 17: Halogens

• Electrons in outer level: 7• Contains only nonmetals• Very reactive because they need to gain only 1

electron to complete valance• Poor conductors of electric current• React violently with alkali metals to form salts• Never found uncombined in nature and combine

readily with other atoms, esp metals• Physical properties of atoms in this group are

different

Group 18: Noble Gases18

• Electrons in outer level: 8 (2 for helium)• Contains nonmetals only• Unreactive under normal conditions• Colorless, odorless gases at room temp• All are found in Earth’s atmosphere in small amounts• Argon is the most abundant noble gas