Metals, Metalloids and Nonmetals

The elements of the periodic table can be broken into three different groups: Metals, Metalloids, and Nonmetals.

This periodic table shows the three different groups of elements. The metalloid group separates the metals from the nonmetals. Elements to the left are metals and nonmetals are to the right. The exception is the element hydrogen. Hydrogen has properties of a nonmetal at normal temperatures and pressures and an alkali metal under extremely high pressure.

Some periodic tables include a zig-zag line to distinguish between metals and metalloids. The line begins below boron (B) and extends between bismuth (Bi) and polonium (Po) or down between livermorium (Lv) and Tennessine (Ts). In reality, the metals near the line often display nonmetallic properties the nonmetals have some metallic character.

Properties of Metals

Most of the elements are metals. Metals include the alkali metal, alkaline earth, transition metal, basic metal, lanthanide, and actinide groups. These elements have metallic character, which means atoms easily lose electrons. Metals display the following properties:

• Solid at room temperature (with the exception of mercury)
• Usually shiny, with metallic luster
• High melting point
• Good conductor of heat
• Good conductor of electricity
• Malleable – able to be pounded into sheets
• Ductile – can be pulled into wire
• High density (exceptions: lithium, potassium and sodium)
• Corrode in air or seawater
• Lose electrons in reactions

Properties of Metalloids or Semimetals

Metalloids or semimetals possess some properties of metals and some of nonmetals. Metalloids typically have several forms or allotropes with very different properties. Characteristics of metalloids include:

• Could be dull or shiny
• Conduct heat and electricity, but not as well as metals
• Good semiconductors
• Usually malleable
• Usually ductile
• Can both gain and lose electrons in reactions

Properties of Nonmetals

The nonmetals include the nonmetals element group, plus the halogens, and noble gases. Properties of nonmetals include:

• Dull, not shiny
• Poor conductor of heat
• Poor conductor of electricity
• Not malleable or ductile, usually brittle
• Lower density (when compared to metals)
• Lower melting point and boiling points (when compared to metals)
• Gain electrons in reactions