Chapter 6Developing The Periodic Table

Part 2

Families on the Periodic Table

• Columns in the periodic table can be grouped into families.

• Families may be one column, or several columns put together.

• Families have names rather than numbers. (Just like your family has a common last name.)

Alkali Metals

Alkali Metals• 1st column on the periodic

table (Group 1) not including hydrogen.

• Most reactive family of metals, always combined with something else in nature (table salt).

• Low density metals (Li, Na and K are less dense than water).

• that are soft enough to cut with a knife.

Alkaline Earth Metals

Ca

Alkaline Earth Metals• Second column on the periodic

table. (Group 2)• Second most reactive family of

metals, always combined with nonmetals in nature.

• All of the alkaline earth metals are found in compound form within the earth's crust.

• Several of these elements are important mineral nutrients (such as Mg and Ca).

Calcium and Magnesium Two Important Minerals

Magnesium & Calcium are essential minerals for your health

• Calcium Found primarily in dairy foods such as milk, cheese and yogurt. Your bones eagerly absorb and store calcium necessary for your body's growth and maintenance until you reach your mid 20's. After that, your body rapidly uses up the calcium to help keep your bones strong. Failure to get enough calcium can lead to osteoporosis (holes in the bones), brittle and easily breakable bones, and tooth loss.

• Magnesium Magnesium is one of the most important minerals your body needs, and fortunately, it can be found in many of the foods we eat, including many fruits, vegetables and dairy products. Failure to get enough magnesium can lead to muscle soreness, heart and blood pressure problems, as well as nervous disorders.

Magnesium Keeps the Doctor at Bay

By W. Gifford-Jones, M.D.Special to The Epoch Times

Apr 24, 2006

                                                                                          Recently, a healthy 18-year-old basketball player and health-conscious jogger died suddenly. The initial diagnosis was death from coronary artery disease due to high blood cholesterol. But the cause of death eventually proved to be magnesium deficiency.

Transition Metals

• Elements in groups 3-12• Less reactive harder

metals• Includes metals used in

jewelry and construction.• Metals used “as metal.”

Less reactive but can still react

Iron (Fe) Rust (Fe2O3)

Oxygen Family or Chalcogens• Elements in group 16• Oxygen is necessary

for respiration.• Many things that stink,

contain sulfur (rotten eggs, garlic, skunks,etc.)

Halogens• Elements in group 17• Most reactive of the

nonmetals.• Always found combined with

other elements in nature.• Have a strong unpleasant

odor and are poisonous (have been used as chemical weapons).

• In low doses can be used as disinfectants (chlorine in drinking water and in pools).

The Noble Gases

• Elements in group 18• All are gases.• VERY non-reactive.• Have a full outer

energy level.

The Octet Rule

• The octet rule states that an atom's outer energy level is full and most stable when it contains eight electrons.

• This stability is the reason that the noble gases are so non-reactive.

• All noble gases other than helium follow the octet rule.

Exception to the Octet RuleThe “Duet Rule”

• The first energy level can only hold two electrons.

• Elements such as Hydrogen and Helium that only have one energy level follow a “duet rule”.

• The duet rule states that two electrons will stabilize an atom with only one energy level.

Rare Earth Elements• The thirty rare earth

elements are composed of the lanthanide and actinide series.

• The rare earth elements are metals.

• Many of these elements are synthetic or man-made. (Primarily elements after plutonium)

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Homework

• Chapter 6 – Worksheet 1