Families of Elements

Lecture Notes Periodic Table

Alkali Metals- Group 1 Alkali metals have one valence electron which

can easily be removed to form a + 1 cation Soft, and shiny metals that react violently with

water Very reactive and can cause burns Reacts quickly with oxygen and therefore it is

never found in its pure form nature Sodium is Alkali metal found in table salt. Potassium

is also found in this family.

Alkaline-Earth Metal- Group 2 Alkaline earth metals have two valence

electrons. They may react with other elements to form

+2 cations. Less active than the Alkali Metals

Calcium is Alkaline-Earth Metal found in shells of sea animals, and in bones and teeth.

Magnesium is used to build some airplanes, it is also found in Epsom salts, and milk of magnesium.

Transition Metals – Groups 3-12 Much less reactive then the Groups one and

two. They can lose electrons to form positive ions.

Silver, gold, platinum, are often used in jewelry because they are shiny and like all metals can be stretched and pounded into different shapes.

Copper is used in electrical wiring or plumbing. Tungsten is used in light bulb filaments. Iron, cobalt, copper, and manganese play a vital

roles in body chemistry.

Boron Family- Group 13 Elements in this family have three valence

electrons They may react with other elements to form

+3 cations Boron is used in detergents Aluminum is the most common metal in the Earth’s

outer layer. Aluminum is also found in cans, foil, and siding.

Carbon Family- Group 14 Elements in this family contain 4 valence

electrons. Carbon in its pure form is graphite or diamond, it

combines with other elements to form millions of carbon containing compounds. Carbon is found in all living substances and in many synthetic.

Silicon is the second most abundant element in the Earth’s outer layer.

Tin is used to coat steel in making rust proof cans.

Nitrogen Family- Group 15 Elements in this family have 5 valence

electrons. Elements in this family may react with other

elements to form an anion with –3 charge. Pure nitrogen exists as a gas. It combines with

carbon, oxygen, and hydrogen to form explosive compounds such as TNT. Its compounds are found in most fertilizers. Nitrogen is found in amino acids and nucleic acids(DNA, RNA).

Phosphorus is a solid which can exist in yellow or red form. It is a basic part of organs and bones.

Oxygen Family- Group 16 Elements in this family have 6 valence

electrons. Elements in this family may react with other

elements to gain 2 electrons to form an anion with –2 charge.

Oxygen is the most common element in the earth’s outer layer. It is basic for almost all life forms. Pure oxygen exists as a gas and is very reactive.

Sulfur is a yellow solid and is used to make matches and rubber tires.

Selenium becomes a good conductor when it is exposed to light; makes it useful for solar cells and light meters.

Halogen Family- Group 17

Elements in this family have 7 valence electrons. Halogens may react with other elements to gain an electron to

form a –1 anion. This family reacts most readily with alkali metals to form white

solids known as salts. Halogen compounds are commonly used in disinfectants and

cleaning agents. Fluorine compounds are used in toothpastes, insecticides

and in the preparation of some plastics. Bromine are used in drugs, photographic film, and in

gasoline to prevent engine knocking.

Noble Gas- Group 18

Element in this family has eight valence electrons in the outer most shell.

All elements in this family are gases. Elements in this family are stable or inert and do not

interact with other elements. This is because their outer energy level is full of electrons. Noble gas elements do not lose or gain electrons to form ions.

Helium is the lightest noble gas and the second most abundant element in the universe. It does not burn and is used in balloons and blimps.

The other elements are used in lighting and welding.

Lanthanides and Actinides Lanthanide family begins with the element

lanthanum, atomic number 57. Some lanthanides are used in the production of steel and glass.

Actinide family begins with the element actinium, atomic number 89. All of the actinides are radioactive they give off high energy particles.