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The chemical elements can be broadly divided into metals, metalloids, and nonmetals according to their shared physical and chemical properties.All elemental metals have a shiny appearance (at least when freshly polished); are good conductors of heat and electricity; form alloys with other metallic elements; and have at least one basic oxide.
Calcium metal melts at 842 °C and boils at 1494 °C; these values are higher than those for magnesium and strontium, the neighbouring group 2 metals. It crystallises in the face-centered cubic arrangement like strontium and barium; above 443 °C (716 K), it changes to a body-centered cubic .
A metalloid is an element that possesses a preponderance of properties in between, or that are a mixture of, those of metals and nonmetals, and which is therefore hard to classify as either a metal or a nonmetal. This is a generic definition that draws on metalloid attributes consistently cited in the literature.
[n 6] Selenium, in particular, is commonly designated as a metalloid in environmental chemistry [n 7] on account of similarities in its aquatic chemistry with that of arsenic and antimony. [n 8] There are fewer references to beryllium, in spite of its periodic table position adjoining the dividing line between metals and nonmetals. Isolated ...
By as early as 1866, some authors began preferring the term "nonmetal" over "metalloid" to describe nonmetallic elements. [204] In 1875, Kemshead [205] observed that elements were categorized into two groups: non-metals (or metalloids) and metals. He noted that the term "non-metal", despite its compound nature, was more precise and had become ...
It is a metalloid and one of the pnictogens, and therefore shares many properties with its group 15 neighbors phosphorus and antimony. Arsenic is a notoriously toxic heavy metal . It occurs naturally in many minerals , usually in combination with sulfur and metals, but also as a pure elemental crystal .
Periodic table extract showing the location of the post-transition metals. Zn, Cd and Hg are sometimes counted as post-transition metals rather than as transition metals. The dashed line is the traditional dividing line between metals and nonmetals. The symbols for the elements commonly recognized as metalloids are in italics. The status of ...
Nonmetals show more variability in their properties than do metals. [1] Metalloids are included here since they behave predominately as chemically weak nonmetals.. Physically, they nearly all exist as diatomic or monatomic gases, or polyatomic solids having more substantial (open-packed) forms and relatively small atomic radii, unlike metals, which are nearly all solid and close-packed, and ...