Light metals are various metals that have a low atomic weight. There is some variation in exactly which metals are classified as heavy and with are considered light. A core group of metals are typically agreed to meet the criteria for being light, while a few others may be classified as either heavy or light. Metals of this type do have a couple of distinguishing characteristics, including the fact that most tend to have a lower level of toxicity than heavy metals.
The core group of metals that are usually classed as light include aluminum, sodium, magnesium, beryllium, and lithium. In some cases, metals that carry a weight up to and including that of nickel are also included in this classification. With metals that are heavier than nickel, there is usually little to no debate about their classification, placing all those firmly into the category of heavy metals. Since there is some difference of opinion regarding whether certain metals should be classed as light or heavy, it is sometimes necessary to determine what criteria is being used to define or class the metals that tend to fall into this gray area before discussing the relative merits of light metals versus heavy metals.
One of the characteristics that tend to set light metals apart from heavy metals is that the light metal alloys tend to be somewhat less toxic than heavier metals. This does not mean that metals of this type are not toxic to some degree; it does mean that as a group, the metals exhibit lower levels of toxicity than those metals typically classed as heavy. There are exceptions to this, with beryllium being a notable example. Another metal that is sometimes classified as light, vanadium, also carries a high amount of toxicity, a factor that sometimes used to justify excluding this metal from the class of light metals.
One of the other characteristics of light metals is the ease with which the materials can be used in the production of different types of products. Within the light metal industry, various metals may be used to create a number of household goods, including casing for electrical appliances. The low atomic weight of the different metals makes them easy to use in light metal casting, which in turn aids in the mass production of a number of goods. Since the metals are relatively easy to work with, a number of the products produced using alloys of this type are relatively inexpensive. The metals can also be used in products that are fit for human consumption, including use as nutritional supplements.