Elements Everywhere!

Elements Everywhere!

• Listen Carefully…

DO NOW

HOMEWORK:

Choose 10 elements from the periodic table (11-86) and do the following:

1.Full electron configuration 2.Noble gas configuration

3.Orbital diagram of ONLY VALENCE

4. Identify by type of element, being as specific as possible

Dmitri Mendeleev

•Arranged elements

according to atomic mass

•Grouped elements according to similar properties

•Left blanks for elements not yet discovered

Henry Moseley

•Studied under Rutherford

•applied X-ray spectra to study atomic structure

•Ordered elements by atomic #

•Killed in action at Gallipoli in 1915

Dobereiner’s Triads

Grouped elements with similar properties

Example:

•Li, K, and Na all react with water and chlorine at room temperature.

•Form hydroxides with similar

formulas: LiOH, NaOH, and KOH.

NEWLAND

•elements show properties that have repeating

patterns when arranged by atomic weight

•Assigned atomic numbers

Periodic Law

What does PERIODIC MEAN????

Elements are arranged in increasing atomic number with repeating trends of similar

properties.

Example: Na is UNDER Lithium instead of next to NE because it is similar to Li.

Periods and Groups

• Horizontal rows in the periodic table are called periods

• Vertical columns are called groups

GROUP I: ALKALI METALS

• 1 VALENCE ELECTRON, S¹

• MOST REACTIVE GROUP OF METALS

• Never found alone

Ductile: Can be drawn into wires

Malleable: Can be pounded into flat sheets

POTASSIUM

•98% of the 120 grams Potassium in the body is within the cells

•of the total potassium,the red blood cells contain 420 mg

•The blood serum contains about 4-5 mg and is a good indication of an individual's potassium

status

Sodium in Salt

• Good for you or Not?

• Speleotherapy ( Cave Therapy) :treatment of respiratory diseases using the air found in

underground caves which is typically rich in natural salt ions

http://www.natural-salt-lamps.com/polishsaltmines.html

FRANCIUM:

THE MOST REACTIVE METAL

Takes only 22 minutes for half of it’s mass to disappear! It is extremely radioactive. Because of its short life and

reactivity, it currently has no significant uses.

GROUP II:ALKALINE EARTH METALS

• Found in Earth’s Crust, always combined with something; very reactive

• 2 valence; s²

• Higher melting and boiling pts. Than alkali and more dense

• Make good bases

Barium

RADIUM

Was mixed other ingredients to create a luminous paint for

applying to the dials and hands of clocks and watches, making them glow.

In the 1920s, young women, most just out of high school, were employed as dial

painters at an East-coast company

.

Strontium-90:

“The Tooth Fairy Project:” 1954 -1982

Sr-90 was found in human vertabre and teeth by U.S. Atomic Energy Commission

Found in healthy adults who died in accidents in New York City, Chicago, and San Francisco, calculated

Conclusion:

*From 1954 to 1964, average amount of Sr-90 per gram calcium in the vertebrae of New York adults rose from

under 0.1 to 2.2

*Peaked in 1964, just after ratification of the Partial Test Ban Treaty by the U.S. that ended American, British, and Soviet

atmospheric nuclear weapons tests

+

Sr-90 deposits Get washed away by rain

Vegetation and water consumed by humans and animals

STRONTIUM acts like CALCIUM!

What do the following solutions have in common?

• CoCl₂ (aq)

• Cr₂O₃(aq)

• CrO₃(aq)

• Ni(NO₃)₂(aq)

•CuSO₄ (aq)

•MnSO₄ (aq)

Transition Metals linking the past to the Future

Example: Iridium

Listen to the video segment to see how Iridium has been

linked to the Ice Age.

Metalloids/Semi-metals –

•Sit on top of the ‘step’

of the periodic table

•Can act as a metal or

nonmetal; can lose or gain electrons

•Boron, Silicon,Arsenic, Tellurium, Astatine

•The Food and Drug Administration yesterday lifted a 14-year ban on the use of silicone gel

breast implants in the United States after decades of contentious debate and litigation over their safety.

New York Times, 11/16/06

•“...for breast reconstruction and cosmetic breast

augmentation, but limited cosmetic use of the implants to women ages 22 and older. “

•According to the federal agency, one study found that 69 percent of women had a rupture.

Silicon: Not just approved for computer chips anymore

GROUP 17: HALOGENS The “salt formers”

• S²p⁵ - 7 valence electrons

• Contains all three phases of matter at room temperature:

Fluorine and Chlorine - gases Bromine - Liquid

Iodine,Astatine - Solid

•Electrons move through filament, bumping into atoms. Lots of energy is made.

•Quantum jumps occur, releasing energy when they return to their ground state

• When heated to a high enough level -- around 4,000 degrees Fahrenheit (2,200 degrees C) they will emit visible light

•Tungsten can withstand high temperatures

•Inert gases allow for it to be redeposited back on filament

Shedding some light on the Halogens...

Incandescent bulbs, including halogen types emit only 5% of their energy to light, the rest goes to heat. But they’re CHEAP!

Incandescents Fluorescents

15 to 20 lumens/watt 60-80 lumens/watt lasts 750 hrs 9375 hrs

. The average American household has 2.5 incandescent lightbulbs on for 4 or more hours each day. If every

household replaced those bulbs with compact fluorescent bulbs, the Nation would save nearly 32 billion kilowatthours every year. That's about 35 percent of all electricity used for

lighting homes. -Department of Energy

Hydrogen

• Colorless, odorless, lighter than air gas

• Placed in Group 1 because it has 1 ve-

• Has both metallic and nonmetallic properties

• Not considered part of any group

Observing properties of Hydrogen

1. Place a SMALL amount of zinc in the test tube (tip full on spatula)

2. Loosely place a stopper on the mouth of the test tube. (just to cover)

3. Observe bubbles forming. After the

reaction has occurred for 1 minutes,

or when you have clearly made a lot

of bubbles, quickly insert a burning

splint into the mouth of the test tube.

Group 18: Noble Gases

Once referred to as the ‘Inert

Gases’ because they did not react with anything...

Now referred to as the ‘Noble’ ones because all other elements marvel at their prestige and the fact they they are lucky to have all 8 valence

electrons.

•In 1962 Newcastle born chemist,Neil Bartlett , created a compound of Xenon and Flourine- a Yellow solid that was

formulated as XePtF₆^-.

Hebrew University of Jerusalem, 2005:

•Combined with basic organic molecules (hydrocarbons)

*xenon, (no negative physiological effects), for anesthetic compounds.

*New fuels that would be more energy efficient/less polluting Ohio State University, 2002:

•created the first-ever compounds of uranium bonded to atoms of argon, krypton, and xenon

No Longer Inert: Some find extreme Nobility