Name that element! It's the ninth most abundant element in Earth's crust. It's as strong as steel but half as heavy, and you might find it in your braces, bike, even candy! What is it? To find out, grab a periodic table and follow these eight clues. Then turn the page to test your chem IQ

Science World, Oct 18, 2002 by Lea Winerman

(CLUE 1) INSIDE SCOOP

Like all elements, this one is composed of atoms, the basic building blocks of matter. Each atom's nucleus, or center, is packed with positively charged protons and neutrally charged neutrons. Outside the nucleus swirl negatively charged electrons. The mystery element has 22 protons in its nucleus.

(Guessed it? You're a chem whiz!)

[ILLUSTRATION OMITTED]

(CLUE 2) ORE-IGINS

This element exists in nature not as a pure element, like gold or sulfur, but as an ore, a mineral compound that contains two or more elements. Ores are mined for industrial uses. The mystery element is extracted from a shiny reddish-brown ore called rutile.

(Need another clue? Read on!)

[ILLUSTRATION OMITTED]

(CLUE 3) BRACE YOURSELF

Combined with the metallic element nickel (NI), the mystery element forms an alloy called nitinol. An alloy is a human-made metal forged from two or more natural metals, like iron and copper. Some hi-tech braces are made of nitinol because it has "shape memory": The metal slowly springs back to its original form when bent. Nitinol braces around crooked teeth eventually tug them straight.

(Nabbed it? Move over, Marie Curie!)

[ILLUSTRATION OMITTED]

(CLUE 4) MELTS IN YOUR MOUTH?

This transition metal combines with oxygen to form a white compound, a molecule made of two or more elements. The compound is an ingredient in paint, paper, and even the white food coloring found on some candies.

(Still searching? More clues ahead ...)

[ILLUSTRATION OMITTED]

(CLUE 5) NO-RUST RACKET

When it comes to tennis rackets, this element is an ace! It reacts with oxygen to form a microscopic coating that protects against corrosion. Some metals, like iron (Fe), corrode when oxidized, or combined with oxygen in air or water. The chemical reaction pulls electrons away from the iron atoms and causes decay. But when this element oxidizes (losing four of its 22 electrons), the reaction forms a thin film of tightly packed molecules on its surface. The film locks out water and oxygen to guard against further corrosion.

(Still stuck? The sixth clue's a charm.)

[ILLUSTRATION OMITTED]

(CLUE 6) IT'S CELL-EMENTAL

Talk is cheap--but not if you're using the Nokia 8910 phone. It will set you back about 1,000! The phone is expensive in part because the casing is crafted from the mystery element, which requires a costly chemical process to isolate it from oxygen. Most metals easily combine with oxygen and exist in nature as metal oxides.

Metal elements, found on the left-hand side of the periodic table, lose outer electrons to non-metal elements, found on the right-hand side of the periodic table. The electron transfer bonds the elements together.

(Mystery solved? Hard work pays off!)

[ILLUSTRATION OMITTED]

(CLUE 7) HEARTFELT INVENTION

The mystery metal is biocompatible: It doesn't react with organic, or carbon-living material like body cause Infections. The medical-friendly element is used in artificial hips, bone-fracture pins, even artificial hearts.

(No idea? Here's your last hint ...)

[ILLUSTRATION OMITTED]

(CLUE 8) PEDAL POWER

This metal is made for pedaling! Its lightness and strength make it perfect bike-frame material. The mystery element has a lower atomic mass than iron, the main metallic element in steel, but a greater atomic mass than the element scandium (Sc). It also has half the density (amount of mass per unit volume) of steel--but is equal in strength.

(Still puzzled? See the TE for the answer.)

[ILLUSTRATION OMITTED]

ANATOMY OF AN ELEMENT

[ILLUSTRATION OMITTED]

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 proton, and hence has a unique atomic number.

ATOMIC MASS equals the number of proton 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.

The Periodic Table

The periodic table is a systematic way to organize Earth's elements, substances that 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. Uranium (U), atomic number 92, is the heaviest. Scientists have created elements with atomic numbers and mass greater than uranium-but they don't exist naturally.

[ILLUSTRATION OMITTED]

IT'S YOUR CHOICE

Test your chemistry IQ! Answer the following questions about elements and the periodic table.

(1) Name the mystery element! --

(2) The element lithium (LI) has an atomic humble of 3. Use this Information to determine its:

A number of protons

B number of electrons

C atomic mass

(3) Sodium (NE) is mast likely to farm a chemical band with:

A sulfur (S)

B zinc (Zn)

C chlorine (Cl)

D potassium (K)

(4) Elements in the same column an the periodic table have similar physical and chemical properties. The mystery element is most similar to which three elements: