What are “Families”? - Giving the Groups “names”

• Groups 1,2, and 13-18 have specific names.

• The specific names are called the group’s family.

Group 1 (The Alkali Metals)

• Group 1 elements are EXTREMELY soft metals (you can actually cut sodium with a butter knife).

• Reactivity increases as you move down the group.

1 2 13 14 15 16

17 18

Group 1 (The Alkali MetalsThe Alkali Metals)• These metals have a single valence electron

(1 electron in the outermost energy level).

• They are so reactive that they are only found combined with other electron acceptors in nature… Reactions occur as they try to GIVE AWAY their one valence electron.

3 p+

4 n0 2 111 p+

12 n0 2 8 1 19 p+

20 n0 2 8 8 1

LITHIUM SODIUM POTASSIUM

Group 1 (The Alkali Metals)

Sodium is so reactive, that a small cube thrown into water will explode (the chemical reaction between sodium and water releases flammable hydrogen gas. The reaction is SO exothermic, that the hydrogen ignites). Exploding Sodium

So why are these elements important to you?

1A

Sodium and Potassium are two essential elements to the human body.

1 2

17 18

13 14 15 16

Importance of Potassium and Sodium

• PotassiumPotassium is essential to muscle and nerve function and keeps the body’s fluids in balance.

• SodiumSodium helps to transport nutrients to the cells and in the body’s fluid balance.

• Both Potassium and Sodium are placed in a group of essential minerals for the body known as “electrolytes”

Will I explode if I eat a potassium-rich banana?

No…REMEMBER -- Calcium and Potassium are SO reactive, you do not find them in an unreacted form

in nature.

Main source of Sodium

Some sources of Potassium

Leg Cramps and DehydrationLeg Cramps and Dehydration

• When athletes train or play hard, they sweat and through your sweat glands they lose a lot of potassium and sodium (the reason that sweat has a salty taste).

• A loss of sodium and potassium has been linked to muscle spasms and cramping due to an inability for wastes to be adequately moved out of the muscles.

…the history of Gatorade

History of Gatorade•Gatorade was first formulated in 1965 in an attempt to help the then struggling Florida Gators football team.

•The formula worked so well against the debilitating effects of dehydration, that Florida began to be known as an effective “second-half” team.

History of Gatorade

•The formula worked so well, that the Gators went on to win their first Orange Bowl in 1967.

•By the late 60s, a case got into the hands of the Kansas City Chiefs and the drink gained national prominence.

Gatorade is loaded with Sodium and Potassium compounds

Group 2: The Alkaline Earth Metals

The Alkaline Earth Metals (Group 2) have two(2) valence electrons.

12

The Alkaline Earth MetalsThe Alkaline Earth Metals

• These metals have two valence electrons (2 electron in the outermost energy level).

• The Alkaline Earth elements want to give up 2 electrons to reach a full outer energy level.

• This is a bit more difficult than Group 1 elements, so the reaction is less violent.

(Group 2) Alkaline Earth characteristics

• These elements are typically harder, denser, and stronger with higher melting points vs. Group 1 Alkali Metals.

Lab DemonstrationLab Demonstration: Reacting of a Group II

Alkaline-Earth Metal:Calcium

Working our Way through the Group 2 elements: Radium

•Radium is EXTREMELY radioactive and not found by itself in nature (will react with hot/cold H2O).

•Gives off a faint blue glow (characteristic known as luminescence).

•Radium is the most reactive of all of the Group 2 elements and will react VIOLENTLY with water of any temperature.

Working our Way through the Group 2 elements: Barium

• Barium is also never found by itself in nature and will react violently with hot/cold water (but not as much as radium).

•Barium can be found in both radioactive and nonradioactive isotopes.

• Barium is used in glass making, rat poison, and x-ray diagnostics.

Barium Swallow Test•Radioactive barium can be used as a medical testing device.

•The barium is administered as a drink and the movement of the barium can be tracked by x-ray through the digestive system, indicating blockages, narrowing of intestines or other health problems.

• Calcium compounds are VERY important to the structure of your teeth and bones.

Working our Way through the Group 2 elements: Calcium

Reacted Calcium in SeashellsThe compound calcium carbonate (CaCO3) is the main component of most seashells and pearls….even chalk (really small seashells).

Magnification of a piece of

everyday chalk.

Natural and “Cultured”

Pearls

Alkaline Earth characteristics

• Example of a Group 2 element: Calcium– Calcium makes up seashells and coral.– These collect on the ocean floor and eventually get

crushed to form limestone.

Calcium Minerals

Gypsum

Selenite

Working our Way through the Group 2 elements: Magnesium

• Magnesium is a key component in photosynthesis and as a activator for processes in the human body.

•Magnesium is essential to ALL known living cells.

• After it has reacted, Magnesium is the lightest of all structural metals and is used to build light-weight objects such as airplanes.

So is Magnesium Reactive?

• The answer is YES… magnesium will react in VERY hot water, but NOT cold water

• It will however burn very brightly when lit (campers lantern).

REACTIVITYREACTIVITY

Transition Metals…they don’t follow the rules!

• Transition metals are elements found in Groups 3-12.

• Transition metals are much less reactive than Group 1 or Group 2 elements.

• With exception of mercury, they are harder, more dense, and have higher melting points vs. Group 1 and 2 elements.

Transition Metals and Valence

• Transition metals can form cations (lose electrons).

• However, transition metals lose electrons that are NOT just the valence…they do weird stuff.

• Gold – can form either Au+ or Au3+