Name that element!

Can you name that element? It can drive you crazy. It's been found in the hair of dead kings and scientists. And dentist use it to plug decaying teeth. Follow these eight clues to find out. Then flip the page to test your chemistry IQ.

DID YOU KNOW?

* The Florida panther is one of more than 20 subspecies of the mountain lion (Puma concolor). "Mountain lion," "catamount," "cougar," and "puma" are all names commonly used to identify these close relatives.

* Unlike ferocious lions, panthers--or any cats from the Puma species--can't roar. These shy cats purr or squeak.

* Panthers can leap to a height of about 6 meters (20 feet). That's almost the height of a two-story building!

CRITICAL THINKING:

* South Florida has a booming human population. Just like Florida panthers, humans depend on the area's natural resources. But conflicting needs can jeopardize the survival of both groups. Discuss: Can humans and panthers coexist?

CROSS-CURRICULAR CONNECTIONS:

History/Geography Research the Panfilo de Narvaez expedition of 1527. Have students pretend they were with Spanish explorer Cabeza de Vaca when he encountered Florida's "lion" (panther). Describe this Scary meeting in a one-page "journal entry."

RESOURCES

* Groller search term: Endangered Species

* Learn about Florida panther conservation at www.panthersociety.org

* Panthers walk with their claws retracted, leaving no claw prints. Learn to tell the difference between feline and canine tracks at www.bear-tracker.com.caninevsfelline.html

CLUE 1

BIG RED

In its pure state, the mystery element is a shiny silver liquid. But in nature, it combines with sulfur to form a bright red mineral (naturally occurring solid made of different elements) called cinnabar. The mineral has been mined for centuries and was even found in Egyptian tombs dating back to 1500 B.C.

GOT IT ALREADY? SCORE 100 POINTS. IF NOT, READ CLUE #2.

CLUE 2

HAIR RAISING

Many historical figures, including scientist Sir Isaac Newton, had traces of this element in their hair. That's because this transition metal easily enters the skin and digestive tract, and is absorbed into every part of the body. Newton is famous for discovering the laws of gravity, but his locks were most likely contaminated during his many experiments with the mystery element.

NABBED THE ANSWER? SCORE 80 POINTS. STILL GUESSING? TAKE THE NEXT CLUE.

CLUE 3

MAD HATTER

In the 19th century, hats were made using this element. The hat makers, called hatters, became ill and went crazy, thus the term "mad as a hatter." That's because this element is a lethal neurotoxin (poison to the central nervous system) when it loses two electrons (negatively charged particles). With two fewer electrons, this element has the same atomic number as platinum.

GAME OVER ALREADY? SCORE 60 POINTS. STILL PLAYING? CHECK OUT CLUE #4.

CLUE 4

FISHY FOOD

The ocean's big fish are full of this element. Industrial pollution containing this element contaminates the water, where bacteria turn it into a highly toxic form. Fish--like tuna and swordfish--eat the toxin-containing bacteria. People eat the fish. "Most poisonings [from this element] are caused by eating contaminated fish," says John Gray, a geologist for the U.S. Geological Survey. So experts say: Eat no more than one serving of these fish per week.

NAME IT NOW? SCORE 40 POINTS. OTHERWISE, READ ON.

CLUE 5

RUB A DUB

This is one strange element. Even though it's a liquid at room temperature, "if you had it in a bathtub you could probably walk across it," says Gray. You could even float a steel ball on it. That's because it has the highest density (mass, or weight, per volume) of any liquid on the periodic table. Anything less dense, including you, will float in it.

HIT ON THE ANSWER? SCORE 20 POINTS IF NOT, KEEP TRYING!

CLUE 6

OPEN WIDE

Chew on this: The silver filling used by dentists to plug cavities, or holes, in teeth is actually made of silver dissolved in the mystery element. Because this element combines so easily with metals, or forms amalgams, it is also used to mine gold. "[This element] has a unique property of being able to stick to gold," says Gray.

SCORE 10 POINTS IF YOU NAME THE ELEMENT WITH THE HELP OF SIX CLUES. STILL GUESSING? READ ON.

CLUE 7

TINY AS A BUTTON

This element powers batteries the size of buttons. The mystery element is stationed at the cathode, or positive end of of battery. While zinc--a member of the same group (column) as the mystery element--is at the anode, or negative end. Electrons flow from zinc to the mystery element, creating an electric current in small devices like watches, calculators, and penlights.

GUESS THE ELEMENT? SCORE 5 POINTS. IF NOT, TRY YOUR LAST CLUE.

CLUE 8

HOT STUFF

You know your body is overheated when this element rises. That's because you find the mystery element inside some thermometers. As your body transfers its heat to the thermometer, the liquid element expands and climbs up the glass tube. The mystery element is also ideal for outdoor thermometers because it won't freeze until -38.9[degrees]C (-38[degrees]F).