Metal
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The term metal refers to all the elements from the periodic table, that display good electrical and thermal conductivity, and possess metallic bonds as the dominant forces between atoms its atoms and molecules.
About 91 of the 118 elements in the periodic table are metals; the others are nonmetals or metalloids. Some elements appear in both metallic and non-metallic forms.[1]
Contents
Metals from the periodic table
- Group I (alkali metals): lithium (Li), sodium (Na), potassium (K), rubidium (Rb), caesium (Cs), francium (Fr).
- Group II (alkaline earth metals): beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), radium (Ra).
- Group III (rare earth metals): scandium (Sc), yttrium (Y), lanthanides, actinides (actinides are not considered Gr. III, but are sometimes included here).
- Group IV: titanium (Ti), zirconium (Zr), hafnium (Hf), rutherfordium (Rf).
- Group V: vanadium (V), niobium (Nb), tantalum (Ta), dubnium (Db).
- Group VI: chromium (Cr), molybdenum (Mo), tungsten (W), seaborgium (Sg).
- Group VII: manganese (Mn), technetium (Tc), rhenium (Re), bohrium (Bh)
- Group VIII: iron (Fe), ruthenium (Ru), osmium (Os), hassium (Hs).
- Group IX: cobalt (Co), rhodium (Rh), iridium (Ir), meitnerium (Mt) (debated).
- Group X: nickel (Ni), palladium (Pd), platinum (Pt), darmstadtium (Ds) (debated).
- Group XI: copper (Cu), silver (Ag), gold (Au), roentgenium (Rg) (debated).
- Group XII (volatile metals): zinc (Zn), cadmium (Cd), mercury (Hg), copernicium (Cn) (debated).
- Group XIII: aluminium (Al), gallium (Ga), indium (In), thallium (Tl), nihonium (Nh) (debated).
- Group XIV: tin (Sn), lead (Pb), flerovium (Fl) (debated).
- Group XV: antimony (Sb), bismuth (Bi), moscovium (Mc) (debated).
- Group XVI: polonium (Po), livermorium (Lv) (debated).
- Group XVII: tennessine (Ts) (debated).
Metals between groups 3 and group 11 (or 12, depending on the definition) are classified as transition metals, while the metals between group 12 and 18 are considered post-transition metals (or poor metals, after old definitions).
Elements from the f-block of the periodic table are called lanthanides and actinides:
- Lanthanides: lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu).
- Actinides: actinium (Ac), thorium (Th), protactinium (Pa), uranium (U), neptunium (Np), plutonium (Pu), curium (Cm), americium (Am), berkelium (Bk), californium (Cf), einsteinium (Es), fermium (Fm), mendelevium (Md), nobelium (No), lawrencium (Lr).
Transitional metals are also grouped after their similar properties, in the following groups:
- Refractory metals: molybdenum, niobium, rhenium, tantalum, tungsten.
- Platinum group metals: ruthenium, rhodium, palladium, osmium, iridium, platinum.
- Precious metals: gold, iridium, osmium, palladium, platinum, rhodium, ruthenium, silver.
General properties
Metals are generally malleable—that is, they can be hammered or pressed permanently out of shape without breaking or cracking—as well as fusible (able to be fused or melted) and ductile (able to be drawn out into a thin wire). Except mercury, all metals are solid at room temperature, though a few, like gallium and caesium have their melting point very close to room temperature.
The chemical properties of metals vary, depending on their position in their periodic table. Elements on the left of the periodic table are very reactive, while the metals from the center and right less so.
Out of the 90 metals, 34 are radioactive, though bismuth is not generally included in the radioactive category due to its extremely long half-life.
Uses
Metals are commonly used to make alloys and conduct electricity.
