The Elements

Periodic Table is more or less broken into metals and nonmetals.

Metals – Left-hand side of the table.

Elements that tend to lose electrons in chemical reactions.

Characteristics of metals

• Good conductors.
• Electricity
• Heat
• Easily shaped.
• Form positive ions.

Why???

• Atoms are stacked in rows – one on top of the other.
  

• Electrons are not tightly held to the nucleus.  Therefore, they form a cloud covering all the nuclei.

• Atoms slide over each other easily and electrons are free to roam.

??? – What is electric current?

Nonmetals - Right Hand Corner

• Nonmetals do not share as many properties in common.

BUT!

• Poor conductors. 

- Heat
- Electricity

• Form negative ions.

Nonmetals are elements that tend to gain electrons.

Electrons are held tightly in the outer energy level!!!

***Metals***

Group 1 – Alkali metals

• Easily lose only electron in outer shell.
• Form ions of +1.
• React violently with water.
• Do not exist free in nature.
• So soft you can cut them with a butter knife.

Examples:
Lithium – Batteries, ceramics, glass making,                       Athlete's foot preparations,
                medications.
Sodium – Drain cleaners, table salt
Potassium – Fertilizers, matches (KNO₃),
                    fireworks, explosives.

*** Potassium and Sodium are important for
      your health.

• Control movements of fluids.
• Transmission of nerve impulses.

Other less common alkali metals.

Cesium and Rubidium are light sensitive and are used in photocells.

Francium – Radioactive.
                   Very unstable.
                   Little is known.


Group 2 – Alkaline Earth Metals

• Lose two instead of one electron.
• Form ions of +2.

Examples:
Calcium and Magnesium dissolve in water to create “hard water”.
Calcium – Needed for strong bones and teeth.
Strontium and Barium are used to create the colors in fireworks.
Barium - used for special X-rays (GI Series).
Radium- Radioactive.
               Discovered by Marie Curie.
               Used to paint faces on watches.
               Radiation treatments for cancer
               patients.

Groups 3-12 - Transition Elements

• Not as reactive – some exist in nature or can be isolated.
• React with oxygen to form oxides (rust).
• Good conductors.

Some are necessary for good health.
Iron – Transportation of O₂ in
           the blood (anemia).

Other examples:
Zinc and Cadmium- Batteries.
Mercury – Mercury fulminate used for detonating explosives.

Some are poisonous – Hg, Ni, and Cd.

Lanthanides and Actinides
Rare Earth Metals (REM)

Monazite – Discovered in 1787 contained all the lanthanides but one.

• Thought to be rare but not!!!

25% of all the metals in the earth's crust are lanthanide.

Actinides have a similar electron configuration.

Examples:
Phosphor dots - Lanthanides
Optical Fibers - Lanthanum
Abrasives – Many REMs

*** Metalloids – Exhibit some but not all of the properties of metals. Used to produce semi- conductors.

Semiconductor – A material that is an insulator of electricity but can act like a conductor under special conditions.

Examples:
Silicon and Selenium

Group 13 – The Boron Family

• Boron is a metalloid.
• All the rest are true metals.

Examples:
Boron – Heat resistant glass and Borax.
Aluminum – Cookware to Aircraft.

Alloys – Solution of two or more metals or a solution of metals and nonmetals.

Examples: Brass = Copper and Zinc
                  Steel = Iron and Carbon
                  S.S. = Iron, Carbon, and
                       Chromium
                  Y. Gold = Gold and Copper
                   W. Gold = Gold and Silver or
                                     Platinum


Alloys of mercury are called amalgams.
Example: Fillings in teeth.

***Nonmetals***

Group 14 - The Carbon Family

Chapter 21 Section 1 Page 485

Carbon (Nonmetal)

• Key to life on earth.
• Can form four covalent bonds due to 4 valence electrons.
• Can bond with other carbon atoms or other elements.
• Forms long chains of carbon atoms that are the backbone of the "molecules of life": proteins, carbohydrates, and fats.
• Exists in several allotropic forms. Each with its own physical properties.

• Graphite - atoms arranged in sheets.
• Uses: lead in your pencil, lubricant.
• Diamond - precise crystalline structure covalently bonded, reason for the extreme hardness.
• Uses: precious gems, industrial cutting operations.

• Organic chemistry is the area of chemistry that studies carbon compounds.

Silicon (Metalloid)

• The second most abundant element on earth.
• Does not exist as a free element - Most common form: SIO₂ or beach sand.
• Uses: Semiconductors, glass making, and silicone (long chains of silicon and oxygen atoms with different carbon chains attached).

Germanium (Metalloid)

• Poor conductor of electricity unless combined with other elements.
• Used to create filters in optical instruments and cameras.
• Not commonly found in nature.

Tin (Metal)

• Very soft metal.
• Used to line metal cans and to make pewter.
• Ingredient in fluoride.

Lead (Metal)

• Used in car batteries.
• Toxic to humans - Leaded gasoline.
• Used for paint pigment - Problem of children eating paint.
• Used in water piping in the distant and not so distant past. Fall of the Roman Empire? Explanation of the disappearance of Sir John Franklin's party in search of the Northwest passage in 1845? (PBS Nova - Buried in Ice)

Group 15 – The Nitrogen Family

• Unique group because the elements show such a variety of properties.

Examples:
Nitrogen – Most abundant gas in the
                  atmosphere.
                  Forms diatomic molecules.
                  Part of the protein molecule.
                  Major component of
                  fertilizer.

Phosphorus – Exist in two different
                       molecular forms called
                       allotropes.
                       Red – Unorganized but
                                     stable.
                      White – Organized but
                                       very unstable.
                       Used for fertilizers and
                       detergents. (pollution)
Arsenic – Poison.
                Two major allotropes.
                Used in insecticides, medicines,
                pressure treated lumber.
                Used to make alloy (Si-As)

Bismuth and Antimony – Used to make
                                         fusible alloys.
                                         (Wood's metal)

Group 16 – Oxygen Family
Oxygen is the most abundant element in the earth's crust.

Oxygen has may forms:
        O₂ – Diatomic
        O₃ – Triatomic (Ozone)

O₂ is converted to O₃ by the sun's UV rays – Ozone layer.
Close to the surface, O₃ is considered a pollutant. (toxic, pungent gas)

Sulfur – Many allotropes.

• Good –Used to create antibiotics.
  

• Bad – SO₂    It stinks and causes acid rain.
  

Tellurium – Used in alloys of lead.
                    It is an exception in the table. It
                    has a larger mass than iodine.

Polonium – Found in uranium ore in
                   1898.
                    Very radioactive.

Group 17 – Halogen Family

• Most reactive of the nonmetals.
• Poisonous.
• Exists as diatomic molecules in  nature.

Examples:
Fluorine – Most reactive.
                 Non-stick cookware.
                 Toothpaste
Chlorine – Bleaches.
                  Disinfectants.
                  Metal cleaners.
                 Your stomach.
Bromine – Change color of dyes.
                 Antiknock agent in gasoline.
                 Pesticides.
                 Fire extinguishers.
Iodine – Purple solid.
              Tincture of iodine
              (alcohol & iodine).
              Needed for growth
              (cretinism).
Astatine – Radioactive.
                 Very rare.
                 Not much known.

Noble Gases (inert gases)
--- Stable Octet ---

Examples:
Helium – Lighter than air
                (balloons).
               Replace N₂ in diver's air
               tanks.
Neon – Neon signs.
Xenon – Flashbulbs.
Radon – Radioactive.
              Radiation treatments for cancer.
              Problems in homes!
                    30% of homes in Maine are
                    above the EPA limits.
              Potential cause of lung cancer.


For more information about the elements go to www.webelements.com.
Note: Pictures on this page are from webelements.com