Metalloids - Key terms



ION:

An atom or group of atoms that has lost or gained one or more electrons, and thus has a net electric charge.

ISOTOPES:

Atoms that have an equal number of protons, and hence are of the same element, but differ in their number of neutrons. This results in a difference ofmass. Isotopes may be either stable or unstable. The latter type, known as radioisotopes, are radioactive.

METALLOIDS:

Elements which exhibit characteristics of both metals and nonmetals. Metalloids are all solids, but are not lustrous or shiny, and they conduct heat and electricity moderately well. The six metalloids occupy a diagonal region between the metals and nonmetals on the right side of the periodic table. Sometimes boron and astatine are included with the metalloids, but in this volume, they are treated as an "orphan" nonmetal and ahalogen, respectively.

METALS:

Elements that are lustrous, or shiny in appearance, and malleable, meaning that they can be molded into different shapes without breaking. They are excellent conductors of heat and electricity, and tend to form positive ions by losing electrons.

NONMETALS:

Elements that have a dull appearance; are not malleable; are poor conductors of heat and electricity; and tend to gain electrons to form negative ions. They are thus the opposite of metalsin most regards, as befits their name.

NORTH AMERICAN SYSTEM:

A version of the periodic table of elements that only numbers groups of elements in which the number of valence electrons equals the group number—that is, the two "tall" columns to the left of the transition metals, as well as the six "tall" columns to the right.

"ORPHAN":

An element that does not belong to any clearly defined family of elements. The metalloids are all "orphans."

RADIOACTIVITY:

A term describing a phenomenon whereby certain isotopes known as radioisotopes are subject to a form of decay brought about by the emission of high-energy particles. "Decay" does not mean that the isotope "rots"; rather, it decays to form another isotope until eventually (though this may take a long time) it becomes stable.

Also read article about Metalloids from Wikipedia

User Contributions:

Comment about this article, ask questions, or add new information about this topic: