Name That Element!

By itself, the mystery element is a smelly, greenish-yellow poisonous gas. Luckily, it’s rarely found alone in nature. That’s because its atoms—the smallest unit of an element—are unstable. They quickly chemically combine with other elements to form compounds. The most common of these compounds is found in large quantities in the ocean. Figured it out already? Score 100 points. Otherwise, read clue #2.

By itself, the mystery element is a smelly, greenish-yellow gas. It’s also poisonous! Good thing it’s almost never found alone in nature. That’s because its smallest units, or atoms, are unstable. They quickly bond with other elements to form compounds. One of these compounds is very common. It’s found in large amounts in the ocean. Figured it out already? Score 100 points. Otherwise, read clue #2.

When water cools to below 0°C (32°F)—its freezing point—it hardens into ice. This physical change often creates slippery streets on winter days. Road crews come to the rescue by scattering a compound made of calcium (Ca) and the mystery element onto roadways. This chemical dissolves in water, lowering the solution’s freezing point. That helps keep the liquid from freezing. Got the answer? Score 80 points. If not, try clue #3.

Water turns into ice when it cools to below 0°C (32°F). That’s its freezing point. This physical change often creates slippery streets on winter days. Road crews come to the rescue. They scatter a compound made of calcium (Ca) and the mystery element onto roads. This chemical melts in water, and it lowers the mixture’s freezing point. That helps keep the liquid from freezing. Got the answer? Score 80 points. If not, try clue #3.

Today, Mars looks like a cold, rocky wasteland. But that might not have always been the case. Last year, NASA’s Curiosity rover discovered traces of boron (B), sodium (Na), and the mystery element within Martian rocks. Sodium is found in the same period (row) on the periodic table as the mystery element. Researchers think these elements were once dissolved in liquid water—a big clue that Mars has a watery history. Know the element? Score 60 points. Need more help? Go to the next clue.

Mars looks like a cold, rocky desert today. But was it always that way? Maybe not. Last year, NASA’s Curiosity rover studied Martian rocks. It found traces of boron (B), sodium (Na), and the mystery element. Sodium and the mystery element are found in the same period (row) on the periodic table. Researchers think these elements used to be dissolved in liquid water. That’s a big clue that Mars had water in the past. Know the element? Score 60 points. Need more help? Go to the next clue.

Combine hydrogen (H) and the mystery element, and you’ll get an acid that is so corrosive it can eat rust off the surface of steel. Believe it or not, your stomach lining produces the same acid. It activates enzymes—proteins that speed up chemical reactions—that your body uses to digest food. Why doesn’t the acid eat holes in your stomach? Your stomach lining protects itself by producing other chemicals that act as antacids, or acid-fighting agents. Solved the mystery? Score 40 points. Not yet? Check out clue #5.

Hydrogen (H) and the mystery element bond to form an acid. It’s so corrosive it can eat rust off the surface of steel. Believe it or not, your stomach lining makes the same acid. It turns on enzymes, proteins that speed up chemical reactions. Your body uses these enzymes to digest food. Why doesn’t the acid eat holes in your stomach? Your stomach lining protects itself by making other chemicals. They act as antacids, or acid-fighting agents. Solved the mystery? Score 40 points. Not yet? Check out clue #5.

When the mystery element combines with calcium (Ca) and oxygen (O)—two other nonmetals—it becomes a powerful disinfectant. It’s used in household cleaners and swimming pools to kill bacteria. The same compound is a strong oxidizer, meaning it causes other chemicals to lose negatively charged electrons. When it is added to laundry, it oxidizes stains. That breaks them down, keeping white clothes bright. Hint: This element has 17 electrons. Cracked the case? Score 20 points. Then go on.

The mystery element can bond with calcium (Ca) and oxygen (O), two other nonmetals. Then it becomes a strong disinfectant. It’s used in household cleaners and swimming pools to kill bacteria. The same compound is a strong oxidizer. That means it causes other chemicals to lose electrons. These tiny particles have a negative charge. Add the compound to laundry, and it oxidizes stains. That breaks them down and keeps white clothes bright. Hint: This element has 17 electrons. Cracked the case? Score 20 points.