Core Concepts – Properties of Metals
In this tutorial, you will learn about the properties of metals, nonmetals, and metalloids (semimetals) as well as examples of metal elements, and nonmetal elements.
Topics Covered in Other Articles
Ductility – the ability to be drawn into wires
Malleability – the ability to be hammered into thin sheets
Luster – the quality of reflecting light from the surface and can be polished
Introduction to Metals, Metalloids, and Nonmetals
An element is a substance that cannot be broken down into any other substance. In other words, an element is the simplest form of matter. Elements are further classified into metals, non-metals, and metalloids (semimetals). Nonmetals are generally on the upper right side of the periodic table, metals cover most of the remaining area with metalloids in-between them.
Properties of Metals
Metals are elements that form positive ions by losing electrons during chemical reactions, except hydrogen. Thus, they are electropositive elements with low ionization energies. Most metals share the properties of being shiny, very dense, and having high melting points. Furthermore, they are ductile, malleable, and lustrous. Metals are also good conductors of heat and electricity. All metals are solids at room temperature, except mercury which is a liquid.
Metals generally form ionic bonds with nonmetals, but there are exceptions. Most metals form at least one basic oxide, although some are amphoteric. Metals exhibit a wide range of reactivity. Special groups of metals include the noble metals Ru, Rh, Pd, Pt, Au, Os, Ir, Ag and the refractory metals Nb, Mo, Ta, W and Re.
- Having a luster (shine) from reflecting light. Some metals will form a patina and the luster is lost.
- Being malleable in their solid state. Gold is the most malleable of all the metals
- Being ductile – which means it can be drawn into a wire. Silver is one of the most ductile metals
- Able to conduct heat and electricity
- Forming cations in aqueous solution by losing their electrons
- Melting point of metals: Metals often have high melting and boiling points, but there are many exceptions to the melting point, like cesium, gallium, mercury, rubidium and tin which all have fairly low melting points. However, most boiling points are still quite high.
- Metals exhibit a wide range of densities, but generally are more dense than nonmetals. Tungsten, platinum, osmium, gold and iridium are extremely dense.
- Most metals are silvery, although some like gold, cesium and copper are colored.
Examples of Metals
Properties of Nonmetals
Nonmetals are elements that form negative ions by gaining electrons during chemical reactions. Thus, they are electronegative elements with high ionization energies. In general, non-metals are brittle, dull, and poor conductors of heat and electricity. They tend to have lower melting points than metals. Most of non-metals exist in two of the three states of matter at room temperature: gases and solids, except bromine, which exists as a liquid.
Examples of Nonmetal Elements
Properties of Metalloids, aka Semimetals
Semimetals, also known as metalloids, have properties of both metals and non-metals. All metalloids are solids. Metalloids can be shiny or dull, but usually have a metallic luster. Some forms of selenium have an amazing, almost space-like sheen.
They are brittle, and are typically semi-conductors. Semi-conductors are capable of conducting electricity better than insulator, but not as well as conductors.
Metalloids generally have chemical properties similar to non-metals. Most form several different anions with oxygen that make a variety of salts with metals, although the aqueous chemistry of germanium is more limited. They act as metals when reacting with halogens, and as non-metals when reacting with alkali metals. Germanium is heavily used in the semiconductor industry.
Some semimetals like selenium and arsenic can be toxic. A selenium speciation machine can measure the amount of selenium present.
Five Main Properties of Metalloids
- Properties intermediate between metals and nonmetals
- Physical appearance similar to metals
- Semi-conductors of electricity
- Chemical properties are more similar to nonmetals than to metals