Heavy metals facts for kids

Crystals of osmium, a heavy metal nearly twice as dense as lead.

Heavy metals are a special group of metals or chemical compounds that contain metals. They are called "heavy" because many of them are quite dense, meaning they pack a lot of mass into a small space. These metals are a big concern for our environment and our health.

The idea of "heavy metals" first came about when scientists learned how harmful metals like cadmium, mercury, and lead could be. All of these are even denser than iron. Over time, the term started to include any other metal or even metalloid (like arsenic) that is toxic, no matter how dense it is.

What Are Heavy Metals?

Heavy metals are natural parts of the Earth's crust. They can be found in rocks, soil, and water. While some metals, like iron and zinc, are important for our bodies in small amounts, others can be very harmful. The "heavy" part of their name often refers to their high density.

Why Are They Important?

Many heavy metals are used in everyday life. For example, copper is used in electrical wires, and chromium is used to make stainless steel. However, when these metals get into the environment in large amounts, they can cause problems. They can pollute water and soil, and they can harm plants, animals, and even people.

Common Heavy Metals

You might have heard of some common heavy metals. These include chromium, cobalt, nickel, copper, zinc, arsenic, selenium, silver, cadmium, antimony, mercury, thallium, and lead. Scientists have tried to create a single, clear definition for "heavy metal," but it's been tricky, and no one definition is used by everyone.

Images for kids

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  Crystals of osmium, a heavy metal nearly twice as dense as lead

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  In a cello (example shown above) or a viola the C-string sometimes incorporates tungsten; its high density permits a smaller diameter string and improves responsiveness.

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  The Statue of Liberty. A stainless steel alloy armature provides structural strength; a copper skin confers corrosion resistance.

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  Neodymium sulfate (Nd2(SO4)3), used to colour glassware

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  The Topaz Solar Farm, in southern California, features nine million cadmium-tellurium photovoltaic modules covering an area of 25.6 square kilometres (9.9 square miles).

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  An X-ray tube with a rotating anode, typically a tungsten-rhenium alloy on a molybdenum core, backed with graphite

See also

In Spanish: Metal pesado para niños