9781422279465

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Helium

number of electrons that surround the nucleus, the atomic mass, and the general size of the atom. The periodic table is a very useful tool as one begins to investigate chemistry and science in general. (For lots more on the periodic table, read Understanding the Periodic Table , another book in this series.) This book is about the element helium. Helium, the second lightest element on the periodic table, has two protons and two neutrons in its nucleus. A stable atom of helium has two electrons. Helium is a gas under standard conditions. How is helium a part of our lives? The most obvious are heli- um-filled balloons that float into the sky. Or maybe, you once sucked the air out of one of those balloons and amused your friends by sounding like Daffy Duck (though that is not really a safe practice). Those are the obvious uses, but helium is used for much more. As you will read, helium has applications in the world of medicine, high tech, and even in exploring space. While it is abundant in space, helium is found only in small quantities on Earth—in fact, it can sometimes be scarce. Because of this, helium is considered to be a nonrenewable resource and efforts are underway to conserve this element. The fu- ture of many things, including your party balloons, may depend on it.

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