Definitions for heavy metals
heavy met·als

WikipediaRate this definition:0.0 / 0 votes

1. Heavy metals

   Heavy metals are generally defined as metals with relatively high densities, atomic weights, or atomic numbers. The criteria used, and whether metalloids are included, vary depending on the author and context. In metallurgy, for example, a heavy metal may be defined on the basis of density, whereas in physics the distinguishing criterion might be atomic number, while a chemist would likely be more concerned with chemical behaviour. More specific definitions have been published, but none of these have been widely accepted. The definitions surveyed in this article encompass up to 96 out of the 118 known chemical elements; only mercury, lead and bismuth meet all of them. Despite this lack of agreement, the term (plural or singular) is widely used in science. A density of more than 5 g/cm3 is sometimes quoted as a commonly used criterion and is used in the body of this article. The earliest known metals—common metals such as iron, copper, and tin, and precious metals such as silver, gold, and platinum—are heavy metals. From 1809 onward, light metals, such as magnesium, aluminium, and titanium, were discovered, as well as less well-known heavy metals including gallium, thallium, and hafnium. Some heavy metals are either essential nutrients (typically iron, cobalt, and zinc), or relatively harmless (such as ruthenium, silver, and indium), but can be toxic in larger amounts or certain forms. Other heavy metals, such as cadmium, mercury, and lead, are highly poisonous. Potential sources of heavy metal poisoning include mining, tailings, industrial waste, agricultural runoff, occupational exposure, paints and treated timber. Physical and chemical characterisations of heavy metals need to be treated with caution, as the metals involved are not always consistently defined. As well as being relatively dense, heavy metals tend to be less reactive than lighter metals and have far fewer soluble sulfides and hydroxides. While it is relatively easy to distinguish a heavy metal such as tungsten from a lighter metal such as sodium, a few heavy metals, such as zinc, mercury, and lead, have some of the characteristics of lighter metals, and, lighter metals such as beryllium, scandium, and titanium, have some of the characteristics of heavier metals. Heavy metals are relatively scarce in the Earth's crust but are present in many aspects of modern life. They are used in, for example, golf clubs, cars, antiseptics, self-cleaning ovens, plastics, solar panels, mobile phones, and particle accelerators.

How to pronounce heavy metals?

1. Alex

   US English

   David

   US English

   Mark

   US English

   Daniel

   British

   Libby

   British

   Mia

   British

   Karen

   Australian

   Hayley

   Australian

   Natasha

   Australian

   Veena

   Indian

   Priya

   Indian

   Neerja

   Indian

   Zira

   US English

   Oliver

   British

   Wendy

   British

   Fred

   US English

   Tessa

   South African

How to say heavy metals in sign language?

Numerology

1. Chaldean Numerology

   The numerical value of heavy metals in Chaldean Numerology is: 2

2. Pythagorean Numerology

   The numerical value of heavy metals in Pythagorean Numerology is: 5

Examples of heavy metals in a Sentence

1. David Bellinger:

   They have much shorter biological half lives than, say, the heavy metals, which can hang around for decades.

2. Jane Houlihan:

   Their brain is forming rapidly, and so when they're exposed to metals that can interrupt those natural processes, the impacts range from behavioral problems to aggression to IQ loss and all kinds of cognitive and behavioral deficits that can persist throughout life, pound for pound, babies get the highest dose of these heavy metals compared to other parts of the population.

3. Jane Houlihan:

   And Healthy Babies , Bright Futures is exactly what Healthy Babies , Bright Futures found -- heavy metals were in foods from every section of the store.

4. Jane Houlihan:

   So many solutions are already available to reduce heavy metals levels in baby food. Companies can require suppliers and growers to test, and can choose ingredients with lower levels. Growers can use soil additives, different growing methods and crop varieties known to reduce lead in their products.

5. Bonnie Baxter:

   We know about dust storms, we know about particulate pollution, we know about heavy metals and how they’re bad for humans, we see a crisis that is imminent.

References

1. ^ Wikipedia
   https://en.wikipedia.org/wiki/Heavy_Metals