Science, Tech, Math Science Nonmetals Definition and Properties Share Flipboard Email Print Cultura / Getty Images Science Chemistry Periodic Table Basics Chemical Laws Molecules Projects & Experiments Scientific Method Biochemistry Physical Chemistry Medical Chemistry Chemistry in Everyday Life Famous Chemists Activities for Kids Abbreviations & Acronyms Biology Physics Geology Astronomy Weather & Climate by Anne Marie Helmenstine, Ph.D. Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels. Updated September 24, 2018 A nonmetal is simply an element that does not display the properties of a metal. It is not defined by what it is, but by what it is not. It doesn't look metallic, can't be made into a wire, pounded into shape or bent, doesn't conduct heat or electricity well, and doesn't have a high melting or boiling point.The nonmetals are in a minority on the periodic table, mostly located on the right-hand side of the periodic table. The exception is hydrogen, which behaves as a nonmetal at room temperature and pressure and is found on the upper left corner of the periodic table. Under conditions of high pressure, hydrogen is predicted to behave as an alkali metal.Nonmetals on the Periodic TableThe nonmetals are located on the upper right side of the periodic table. Nonmetals are separated from metals by a line that cuts diagonally through the region of the periodic table containing elements with partially filled p orbitals. The halogens and noble gases are nonmetals, but the nonmetal element group usually consists of the following elements:hydrogencarbonnitrogenoxygenphosphorussulfurseleniumThe halogen elements are:fluorinechlorinebromineiodineastatinePossibly element 117 (tennessine), although most scientists think this element will behave as a metalloid.The noble gas elements are:heliumneonargonkryptonxenonradonelement 118 (oganesson). This element is predicted to be a liquid but is still a nonmetal. Properties of NonmetalsNonmetals have high ionization energies and electronegativities. They are generally poor conductors of heat and electricity. Solid nonmetals are generally brittle, with little or no metallic luster. Most nonmetals have the ability to gain electrons easily. Nonmetals display a wide range of chemical properties and reactivities. Summary of Common PropertiesHigh ionization energiesHigh electronegativitiesPoor thermal conductorsPoor electrical conductorsBrittle solids—not malleable or ductileLittle or no metallic lusterGain electrons easilyDull, not metallic-shiny, although they may be colorfulLower melting points and boiling point than the metalsComparing the Metals and NonmetalsThe chart below displays a comparison of the physical and chemical properties of the metals and nonmetals. These properties apply to the metals in general (alkali metals, alkaline earth, transition metals, basic metals, lanthanides, actinides) and nonmetals in general (nonmetals, halogens, noble gases). MetalsNonmetalschemical propertieseasily lose valence electronseasily share or gain valence electrons 1-3 electrons (usually) in the outer shell4-8 electrons in the outer shell (7 for halogens and 8 for noble gases) form basic oxidesform acidic oxides good reducing agentsgood oxidizing agents have low electronegativityhave higher electronegativityphysical propertiessolid at room temperature (except mercury)may be liquid, solid, or gas (noble gases are gases) have metallic lusterdo not have metallic luster good conductor of heat and electricitypoor conductor of heat and electricity typically malleable and ductileusually brittle opaque in a thin sheettransparent in a thin sheet Continue Reading