EESA10H3 Lecture 5: Human Health and the Environment 5
4 Jun 2016
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Document Summary
Even ones that are essential can be toxic in some concentrations. We say that heavy metals are all elements that have metallic characteristics but they also have a very high atomic weight number one definition is based on atomic weight. The second definition says that it is based on the density of the element density of elemental forms of these metal. They say that all elements that have density higher than 7g/cm3 belong to this group. Some other scientists say that this is not true we are going to base this definition on a specific gravity. We actually don"t know or don"t agree with what heavy metals are and not only that. Some elements known as metalloids (not really truly metals) Arsenic is it doesn"t have full characteristics but we still consider arsenic as a heavy metal. There is another term that is very often used and seen in literature; this is known as trace elements.
