Metals vs Nonmetals


Quick comparison of metals vs nonmetals
Quick comparison of metals vs nonmetals

Elements may be classified as metals, nonmetals, or metalloids. Elements with some characteristics of metals and some of nonmetals are metalloids. Metals are on the left side of the periodic table. Nonmetals are on the right side of the table. Metalloids occur in zig-zag line on the table, separating metals and nonmetals. Here is a look at the difference between metals and nonmetals.

Periodic Table-Metals 2017
Metals, metalloids, and nonmetals on the periodic table
MetalsNonmetals
Metallic luster (shiny)Not lustrous
Good conductors of heat and electricityPoor conductors of heat and electricity
Malleable – can be beaten into sheetsBrittle solids
Ductile – can be stretched into wireNonductile
Opaque thin sheetsTransparent thin sheets
Sonorous (bell sound when struck)Not sonorous
Usually solid at room temperatureSolid, liquid, or gas at room temperature
Form cations (positive-charged ions)Form anions (negative-charged ions)
Usually 1-3 electrons in outer shellUsually 4-8 electrons in outer shell
Form basic oxidesForm acidic oxides
Good reducing agentsGood oxidizing agents
Low electronegativityHigh electronegativity
Low ionization energyHigh ionization energy
Mostly high melting pointsLow melting points
Intermediate to large atomic radiusSmall to intermediate atomic radius
Comparison of the chemical and physical properties of metals and nonmetals.

Metals

About 75% of elements on the periodic table are metals. Because so many elements are metals, they are subdivided into smaller groups, including the alkali metals, alkaline earth metals, transition metals, post-transition or basic metals, lanthanides, and actinides. Most metals are easy to recognize by their shiny, metallic appearance. But, they share other properties in common with each other.

Metal Physical Properties

  • Lustrous (shiny)
  • Good conductors of heat and electricity
  • High melting point
  • High density (heavy for their size)
  • Malleable (can be hammered)
  • Ductile (can be drawn into wires)
  • Usually solid at room temperature (an exception is mercury)
  • Opaque as a thin sheet (can’t see through metals)
  • Metals are sonorous or make a bell-like sound when struck

Metal Chemical Properties

  • Have 1-3 electrons in the outer shell of each metal atom and lose electrons readily
  • Corrode easily (e.g., damaged by oxidation such as tarnish or rust)
  • Lose electrons easily
  • Form oxides that are basic
  • Have low electronegativity values
  • Are good reducing agents

Nonmetals

Nonmetals include the nonmetal, halogen, and noble gas groups on the periodic table. While most metals are solid at room temperature, there nonmetallic solids, liquids, and gases. The nonmetals are a diverse collection of elements, but they share some common properties.

Nonmetal Physical Properties

  • Not lustrous (dull appearance, sometimes colorless)
  • Poor conductors of heat and electricity
  • Nonductile solids
  • Brittle solids
  • May be solids, liquids or gases at room temperature
  • Transparent as a thin sheet
  • Nonmetals are not sonorous

Nonmetal Chemical Properties

  • Usually have 4-8 electrons in their outer shell
  • Readily gain or share valence electrons
  • Form oxides that are acidic
  • Have higher electronegativities
  • Are good oxidizing agents

Metalloids

It’s helpful to know the difference between metals and nonmetals in order to identify metalloids. Metalloids have some properties of metals and some properties of nonmetals. In general, metalloids often appear metallic, but are more likely to be semiconductors than conductors. Like nonmetals, metalloids are neither malleable nor ductile. While solid at room temperature, metalloids have lower melting points than most metals. Metalloids have electronegativity values intermediate between metals and nonmetals.

References

  • Askeland, D.R.; Fulay, P.P.; Wright, J.W. (2011). The Science and Engineering of Materials (6th ed.). Cengage Learning, Stamford, CT. ISBN 0-495-66802-8.
  • Lide, D.R.; Frederikse, H.P.R. (eds.) (1998). CRC Handbook of Chemistry and Physics (79th ed.). CRC Press, Boca Raton, Florida. ISBN 0-849-30479-2.
  • Tilley, R.J.D. (2004). Understanding Solids: The Science of Materials (4th ed.). John Wiley, New York.

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