CLUE 1
ELEMENTAL
It fills almost one half of Earth's crust, 21 percent of the atmosphere, and two thirds of the human body. In nature, it's rare to find a lone atom of this element. Instead, the mystery element exists mostly as a colorless, odorless gas made of diatomic molecules (two identical atoms joined to form a chemical bond).
GOT IT ALREADY? SCORE 100 POINTS. IF NOT, READ CLUE #2.
CLUE 2
CAR WRECKER
This nonmetal is one of the most reactive (chemically active) elements of the periodic table. It automatically yanks electrons (negatively charged particles that orbit an atom's center, or nucleus) away from almost every element. When iron atoms lose electrons to the mystery element, the metal corrodes, or forms rust on cars, ships, and bridges.
NABBED THE ANSWER? SCORE 80 POINTS. STILL GUESSING? TAKE THE NEXT CLUE.
CLUE 3
WHITE OUT
The mystery element is the active ingredient in commercial hair bleach. It breaks down the natural pigments (compounds that reflect a certain color of light) in hair follicles to wipe out color, leaving a gleaming white mane.
GAME OVER ALREADY? SCORE 60 POINTS. STILL PLAYING? CHECK OUT CLUE #4.
CLUE 4
LIFTOFF
Rockets use this element's liquid form to blast into space at over 27,358 kilometers per hour (17,000 mph). Much like a car engine, the rocket uses this element in the process of combustion (burning fuel). But while a car sucks the element from the air, a rocket needs so much of this element that it's equipped with storage tanks that feed into the spacecraft's main engines. The engines consume more than 1.59 million kg (3.5 million lbs) of fuel in only eight minutes.
NAME IT NOW, SCORE 40 POINTS.
CLUE 5
BUSTED
Cross-country ski champ Johann Muehlegg was stripped of a gold medal at the 2002 Winter Olympics, when officials caught him using a drug that pumps up this element in the blood: Darbepoetin helps patients with kidney failure increase the production of red blood cells. But some athletes inject the drug to gain strength and speed: "The more of this element you can get to the tissue, the more your muscles work," says Larry Bowers at the U.S. Anti-Doping Agency. Red blood cells carry the mystery element to the muscles--where it burns food for fuel.
HIT ON THE ANSWER? SCORE 20 POINTS. IF NOT, KEEP TRYING!
CLUE 6
ZIT KILLER
Acne is caused by anaerobic bacteria, or single-celled organisms that die in the presence of this element. Propionibacterium acnes (bacteria that cause acne) burrow into pores under your skin and release toxic chemicals that cause red, pus-filled zits. Most popular acne creams deliver the mystery element to clogged pores--it kills the bacteria and clears your face.
SCORE 10 POINTS IF YOU NAME THE ELEMENT WITH THE HELP OF SIX CLUES. STILL GUESSING? READ ON.
CLUE 7
BLOOD LINES
On clear, dark nights, eerie bands of light, known as the aurora borealis, pulse through the northern sky. When high-energy particles from the sun bombard Earth's atmosphere, excited atoms of this element create the green and red colors of the northern lights. Periods of intense energy turn the sky blood red. "The lights scared medieval Europeans," says geophysicist Charles Deehr at the University of Alaska in Fairbanks. They believed the vibrant red sky signaled the outbreak of war.
GUESS THE ELEMENT? SCORE 5 POINTS. IF NOT, TRY YOUR LAST CLUE.
CLUE 8
HEALTHY HIGH
Some health bars and nightclubs offer a whiff of this element to patrons who shell out $1 a minute to breathe in the pure gas. It comes in a variety of flavors, including peppermint, cranberry, and wintergreen. But most health buffs who inhale it believe the element relieves stress, increases energy, and reduces headaches. So far, the U.S. Food and Drug Administration isn't buying into the healthy high.
STILL NO ANSWER? TURN TO PAGE 20.
ANATOMY OF AN ELEMENT
X--Atomic number
??--Element symbol
Name--Element name
X.XXXX--Average atomic mass
Key definitions:
ATOMIC NUMBER equals the number of protons (positively charged particles) in an atom's nucleus, or center. Every element contains a different number of protons, and hence has a unique atomic number.
ATOMIC MASS equals the number of protons plus the number of neutrons found in a single atom of an element. The weight of an atom resides in its nucleus, which houses both protons and neutrons.
[ILLUSTRATION OMITTED]
The periodic table is a systematic way to organize Earth's elements, which can't be broken down into simpler substances. Today, there are 112 known and named chemical elements. Elements are arranged according to their increasing atomic number. Hydrogen (H), for example, has an atomic number of 1 and is the lightest known natural element on Earth. Scientists have created elements with atomic numbers greater than 92--but they don't exist naturally.
IT'S YOUR CHOICE
Test your chemistry IQ! Answer the following questions about elements
and the periodic table.
1. Name the mystery
element!
--
2. Which element
has 36 electrons
orbiting its nucleus?
A Aluminum
B Krypton
C Antimony
D Beryllium
3. Elements in the
same group on the
periodic table have
similar chemical
properties. The
mystery element
typically gains two
electrons when it
forms a chemical
bond. Which of the
following elements
is likely to do the
same?
A Calcium
B Fluorine
C Carbon
D Sulfur
4. Which of the
following statements
is not true?
A Atoms form chemical
bonds by exchanging
electrons.
B Atoms form chemical
bonds by exchanging protons.
C More than two
atoms can form a
chemical bond.
D A chemical bond
can be broken.
5. Seven
nonmetal
elements exist
naturally as
diatomic molecules.
Which of
these molecules
is not in its
natural state?
A [N.sub.2]
B [Br.sub.2]
C [K.sub.2]
D [H.sub.2]
OZONE is a molecule made of three atoms of the mystery element. In the ozone layer of Earth's atmosphere it shields humans from the sun's harmful rays. But pollutants seem to have blown a hole in the ozone layer.
Did You Know?
* The reactions in which elements combine with oxygen to form an oxide were among the first to be studied by early chemists, who called them oxidation reactions. The term is now used to describe any reaction in which an element loses electrons to another substance.
* Oxygen free radicals are oxygen atoms that have at least one unpaired electron orbiting the nucleus. In the body, free radicals are a byproduct of energy production that damage cells. Many scientists believe oxygen free radicals play a significant role in aging.
* Oxygen gas produces the foam when you use hydrogen peroxide to clean a cut or scrape.
Cross-Curricular Connection
Health/Physical Education/Math: The best way to see how hard you exercise is to measure the amount of oxygen in your blood. But because this is difficult to do, many athletes approximate this measurement by monitoring their heart rate. use this equation to approximate your maximum heart rate, or the heart rate you'll have when you're exercising the hardest. Max heart rate (beats per minute) = 220 - your age. Now test how hard you exercise: Run for 5 to 10 minutes, then count the number of beats in your pulse for one minute. What percentage of your max heart rate did you achieve?
Critical Thinking: Some athletes sleep at high altitudes or in low-oxygen tents and train at low altitudes before major competitions. What advantage would this give them and why? Should this practice be banned?
Resources
This high school textbook has some excellent pictures and descriptions of everyday uses of oxygen: Chemistry: Concepts and Applications, Glencoe/McGraw-Hill, 2002.
Basic chemical information on each element is available on the web at: www.webelements.com
Experiment with oxidation: This step-by-step experiment from Michigan State University explores why fruits turn brown in the air and how can you prevent it: agexted.cas.psu.edu/docs/29503198.html
We use our lungs to breathe in oxygen. But do insects and fish? Compare how other forms of life get the oxygen they need at this interactive site: www.sk.lung.ca/content.cfm/compare
More information on auroras, and a daily aurora forecast from Professor Charles Deehr is available at the University of Alaska's geophysical institute: www.pfrr.alaska.edu/~pfrr/AURORA/INDEX.HTM
Name That Element!
1. Oxygen 2. b 3. d 4. d 5. c