STANDARDS

NGSS: Core Idea: PS1.A

CCSS: Literacy in Science: 7

TEKS: 6.6A, 7.6A, 8.5A, 8.5B, C.5A, C.5B

Name That Element!

Which element helps scientists see distant planets, keeps armpits dry, and can be a real gem? Follow these five clues to find out. Then show what you know about the periodic table.

BJOERN WYLEZICH/SHUTTERSTOCK.COM

PAIRED UP

PAIRED UP

In its pure form, the mystery element is gray and shiny—but you won’t find this form in nature. Although it’s the most abundant metal in Earth’s crust, or outer layer, the mystery element is always found in compounds. That’s because it’s highly reactive and bonds easily with other elements. The raw version of the mystery element has to be extracted from mineral-bearing rocks called oreGot it already? Score 100 points. If not, try clue 2.

The mystery element’s pure form is gray and shiny. But you won’t find this form in nature. It’s the most common metal in Earth’s crust, or outer layer. Even so, the mystery element is always found in compounds. That’s because it’s highly reactive and bonds easily with other elements. The raw version of this element must be removed from mineral-bearing rocks called ore. Got it already? Score 100 points. If not, try clue 2.

ESO/JOSE FRANCISCO SALGADO/SCIENCE SOURCE

STAR SPOTTER

STAR SPOTTER

Telescopes allow astronomers to view distant objects in space. Some of these instruments focus light using mirrors coated with a thin layer of the mystery element. To make a telescope mirror, the mystery element is heated inside a vacuum, or airless space. The metal evaporates, turning into gas, and its molecules settle on the mirror. When cooled, the coating solidifies, giving the mirror a shiny, reflective surface, explains Andrew R. Barron, a chemistry professor at Rice University in Texas. Know the answer? Score 80 points. Otherwise, go to clue 3.

Astronomers use telescopes to view distant objects in space. Some telescopes focus light with mirrors. A thin layer of the mystery element coats the mirrors. To make a telescope mirror, the mystery element is heated inside a vacuum. That’s a space with no air. The metal evaporates, or turns into gas. Then its molecules settle on the mirror. When it’s cooled, the coating becomes solid. That gives the mirror a shiny, reflective surface, explains Andrew R. Barron. He’s a chemistry professor at Rice University in Texas. Know the answer? Score 80 points. Otherwise, go to clue 3.

SHOTPRIME STUDIO/SHUTTERSTOCK.COM

NO SWEAT!

NO SWEAT!

The mystery element helps fight underarm sweat. Most antiperspirants contain a compound made of the mystery element and chlorine (Cl), a member of the same period, or row, on the periodic table. Sweat reacts with the antiperspirant, causing the compound to precipitate out. That means solid particles of the compound separate from the antiperspirant mixture. These particles plug the openings of tiny sweat glands in your skin so perspiration can’t escape. Figured it out? Score 60 points. Need more help? Read clue 4.

The mystery element helps fight underarm sweat. Most antiperspirants contain a compound made of the mystery element and chlorine (Cl). These two elements are in the same period, or row, on the periodic table. Sweat reacts with the antiperspirant. It causes the compound to precipitate out. That means solid particles of the compound separate from the antiperspirant mixture. These particles plug the openings of tiny sweat glands in your skin. Then sweat can’t escape. Figured it out? Score 60 points. Need more help? Read clue 4.

ELNUR/SHUTTERSTOCK.COM

SEEING RED

SEEING RED

When a compound made of the mystery element and oxygen (O) is exposed to high temperatures deep inside Earth, it forms clear crystals of corundum. It’s the second-hardest mineral on Earth, after diamond. Sometimes, traces of the element chromium (Cr), which has 11 more protons in its nucleus than the mystery element, are also present in corundum crystals. That causes them to turn red, forming rubies, explains gemologist Hanna Cook-Wallace of Studio Jewelers in Wisconsin. Game over? Score 40 points. If not, there’s still one final clue.

Deep inside Earth, a compound of the mystery element and oxygen (O) is exposed to high temperatures. Then it forms clear crystals of corundum. It’s the second-hardest mineral on Earth, after diamond. Sometimes, tiny amounts of the element chromium (Cr) are also in corundum crystals. Chromium has 11 more protons in its nucleus than the mystery element. The chromium turns the crystals red. That’s how rubies form, explains Hanna Cook-Wallace, a gemologist at Studio Jewelers in Wisconsin. Game over? Score 40 points.  If not, there’s still one final clue.

ISTOCKPHOTO/GETTY IMAGES

RECYCLE IT

RECYCLE IT

Drinks and foods are often sold in containers made from the mystery element, which has 13 protons. That’s because this metal is lightweight, doesn’t rust, and is malleable, or capable of being shaped. When you’re done using these containers, don’t toss them in the trash: The mystery element can be recycled. Melting it down to make new products uses less energy and generates less waste and pollution than mining more of the mystery element. Write your answer and score 20 points. Then scroll on.

Drink and food containers are often made from the mystery element, which has 13 protons. That’s because this metal is lightweight and doesn’t rust. It’s also malleable, meaning it can be shaped. When you’re done with these containers, don’t throw them away. The mystery element can be recycled. It’s melted down to make new products. That uses less energy than mining more of this element. It also creates less waste and pollution. Write your answer and score 20 points. Then continue.

Show What You Know

Use the periodic table and what you learned about the mystery element to answer the following questions.

1.

A compound is made up of ____.

1.

A compound is made up of ____.

A. only one element

B. two or more elements bonded together

C. a metal

D. a single atom


A. only one element

B. two or more elements bonded together

C. a metal

D. a single atom


2.

Which of the following elements is a metal?

2.

Which of the following elements is a metal?

A. silicon (Si)

B. argon (Ar)

C. hydrogen (H)

D. francium (Fr)


A. silicon (Si)

B. argon (Ar)

C. hydrogen (H)

D. francium (Fr)


3.

Which of the following is NOT found in group 13?

3.

Which of the following is NOT found in group 13?

A. boron (B)

B. gallium (Ga)

C. indium (In)

D. polonium (Po)


A. boron (B)

B. gallium (Ga)

C. indium (In)

D. polonium (Po)


4.

Which of the following is NOT found in the same period as the others?

4.

Which of the following is NOT found in the same period as the others?

A. chromium (Cr)

B. tungsten (W)

C. nickel (Ni)

D. arsenic (As)


A. chromium (Cr)

B. tungsten (W)

C. nickel (Ni)

D. arsenic (As)


5.

Of the following elements, which is the heaviest solid metal?

5.

Of the following elements, which is the heaviest solid metal?

A. iron (Fe)

B. zirconium (Zr)

C. gold (Au)

D. astatine (At)


A. iron (Fe)

B. zirconium (Zr)

C. gold (Au)

D. astatine (At)


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