General Properties of Metals
Learning Objective
- Recall the general properties of metallic elements.
Key Points
- The electrical and thermal conductivities of metals originate from the fact that their outer electrons are delocalized.
- Metals can be viewed as a collection of atoms embedded in a sea of electrons, which are highly mobile.
- Metals are usually inclined to form cations through electron loss, reacting with oxygen in the air to form oxides over various timescales: for example, iron rusts over years, while potassium burns in seconds.
- Metals are typically malleable and ductile, deforming under stress without cleaving, and they are also shiny and lustrous.
Terms
- ductileCapable of being pulled or stretched into thin wire by mechanical force without breaking.
- conductiveAble to conduct electrical current or heat.
- metalAny of a number of chemical elements in the periodic table that form a metallic bond with other metal atoms; generally shiny, somewhat malleable and hard, often a conductor of heat and electricity
A metal can refer to an element, compound, or alloy that is a good conductor of both electricity and heat. Example metals include gold, sodium, copper, iron, and many other elements. Metals are usually malleable, ductile, and shiny.
Density of Metals
Metals typically consist of close-packed atoms, meaning that the atoms are arranged like closely packed spheres. In a metal, atoms readily lose electrons to form positive ions (cations). Those ions are surrounded by de-localized electrons, which are responsible for the conductivity. The solid produced is held together by electrostatic interactions between the ions and the electron cloud, which are called metallic bonds.Metals are shiny and lustrous with a high density. They have very high melting and boiling points because metallic bonding is very strong, so the atoms are reluctant to break apart into a liquid or gas.
Conductivity of Metals
Metals in general are conductive, with high electrical conductivity and high thermal conductivity. Typically they are malleable and ductile, deforming under stress without cleaving. For example, hitting a metal with a hammer will "dent" the metal, not shatter it into pieces.The electrical and thermal conductivities of metals originate from the fact that their outer electrons are delocalized. This means the electrons are not locked into any one atom but can move freely throughout the metal. Metals can be viewed as a collection of atoms embedded in a sea of electrons, which are highly mobile. This is very instrumental in the conductivity of the metal.
Show Sources
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"General Chemistry/Metallic bonds."
http://en.wikibooks.org/wiki/General_Chemistry/Metallic_bonds
WikibooksCC BY-SA 3.0.
"General Chemistry/Chemistries of Various Elements/Group 1."
http://en.wikibooks.org/wiki/General_Chemistry/Chemistries_of_Various_Elements/Group_1
WikibooksCC BY-SA 3.0.