Metals, Nonmetals, and Metalloids of the Periodic Table

Rare earth metals, conceptual image

DAVID MACK / Getty Images

Elements of the periodic table are grouped as metals, metalloids or semimetals, and nonmetals. The metalloids separate the metals and nonmetals on a periodic table. Also, many periodic tables have a stair-step line on the table identifying the element groups. The line begins at boron (B) and extends down to polonium (Po). Elements to the left of the line are considered metals. Elements just to the right of the line exhibit properties of both metals and nonmetals and are termed metalloids or semimetals. Elements to the far right of the periodic table are nonmetals. The exception is hydrogen (H), the first element on the periodic table. At ordinary temperatures and pressures, hydrogen behaves as a nonmetal.

Properties of Metals

Most elements are metals. Examples of metals include iron, tin, sodium, and plutonium. Metals exhibit the following properties:

  • Usually solid at room temperature (mercury is an exception)
  • High luster (shiny)
  • Metallic appearance
  • Good conductors of heat and electricity
  • Malleable (can be bent and pounded into thin sheets)
  • Ductile (can be drawn into wire)
  • Corrode or oxidize in air and seawater
  • Usually dense (exceptions include lithium, potassium, and sodium)
  • May have a very high melting point
  • Readily lose electrons

Properties of Metalloids or Semimetals

Examples of metalloids include boron, silicon, and arsenic. Metalloids have some of the properties of metals and some nonmetallic characteristics.

  • Dull or shiny
  • Usually conduct heat and electricity, though not as well as metals
  • Often make good semiconductors
  • Often exist in several forms
  • Often ductile
  • Often malleable
  • May gain or lose electrons in reactions

Properties of Nonmetals

Nonmetals exhibit very different properties from metals. Examples of nonmetals include oxygen, chlorine, and argon. Nonmetals display some or all of the following characteristics:

  • Dull appearance
  • Usually brittle
  • Poor conductors of heat and electricity
  • Usually less dense, compared to metals
  • Usually low melting point of solids, compared with metals
  • Tend to gain electrons in chemical reactions
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Your Citation
Helmenstine, Anne Marie, Ph.D. "Metals, Nonmetals, and Metalloids of the Periodic Table." ThoughtCo, Aug. 29, 2020, Helmenstine, Anne Marie, Ph.D. (2020, August 29). Metals, Nonmetals, and Metalloids of the Periodic Table. Retrieved from Helmenstine, Anne Marie, Ph.D. "Metals, Nonmetals, and Metalloids of the Periodic Table." ThoughtCo. (accessed June 8, 2023).