Metals vs Nonmetals: What's the Difference?

Look at a periodic table and most of it is metals — but the small patch of nonmetals on the right side includes oxygen, carbon, and nitrogen, the elements life is made of. Telling the two groups apart is one of the first skills that makes the periodic table feel readable.

The short answer: metals tend to be shiny, conduct electricity, bend without breaking, and lose electrons. Nonmetals tend to be dull, don't conduct, are brittle when solid, and gain or share electrons. On the periodic table, a zig-zag staircase line separates the metals (left and centre) from the nonmetals (upper right).

Quick comparison at a glance

Feature Metals Nonmetals
Position on the table Left and centre (most of it) Upper right
Appearance Shiny (lustrous) Dull
Electrical/heat conductivity Good conductors Poor (insulators)
When solid Malleable & ductile (bend, stretch) Brittle (shatter)
State at room temperature Mostly solid (mercury is liquid) Gases, liquids, or solids
Electrons in bonding Tend to lose them → form cations Tend to gain/share them → form anions
Examples Iron, copper, sodium, gold, aluminium Oxygen, carbon, nitrogen, sulfur, chlorine

The rest of the post just unpacks those rows — and the handful of exceptions worth knowing.

What makes a metal a metal

Most elements are metals, and they share a recognisable personality:

  • Shiny when freshly cut, because of how their surface electrons interact with light.
  • Good conductors of heat and electricity, thanks to electrons that can move freely.
  • Malleable (can be hammered into sheets) and ductile (can be drawn into wires) — they bend rather than snap.
  • Usually have few valence electrons (1–3), which they give up fairly easily. That's why metals form positive ions (cations) and why they sit on the electron-donating side of bonding.

Think copper wiring (conducts), gold leaf (malleable), or an iron beam (strong, solid).

What makes a nonmetal a nonmetal

Nonmetals are fewer, but they punch above their weight — they make up most of the living world. Their typical traits are the mirror image of metals:

  • Dull rather than shiny.
  • Poor conductors (most are insulators).
  • Brittle when solid — they crack instead of bending.
  • Often gases (oxygen, nitrogen) or low-melting solids; bromine is a rare liquid nonmetal.
  • Usually have many valence electrons (4–7), so they tend to gain or share electrons, forming negative ions (anions) or covalent bonds.

Don't forget the metalloids

A few elements sit right on the staircase line and behave like a blend of both — the metalloids: boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), and tellurium (Te). Silicon is the famous one: it conducts some electricity (a "semiconductor"), which is exactly why it runs every computer chip.

Worked examples

Classify each, then check:

  • Copper (Cu): shiny, conducts, bends → metal.
  • Sulfur (S): dull, brittle yellow solid → nonmetal.
  • Silicon (Si): on the staircase, semiconductor → metalloid.
  • Bromine (Br): dull, poor conductor (and a liquid!) → nonmetal.
  • Aluminium (Al): light, shiny, conducts → metal.

Common mistakes to avoid

  • Assuming every metal is solid. Mercury is a liquid at room temperature and still a metal.
  • Assuming nonmetals never conduct. Graphite (a form of carbon) conducts electricity — a famous exception.
  • Forgetting metalloids exist. Elements on the staircase line aren't cleanly one or the other.
  • Misplacing hydrogen. It's usually printed above Group 1, but hydrogen is a nonmetal, not a metal.

FAQ

Where are metals on the periodic table?
On the left and centre — the large majority of the table. Nonmetals cluster in the upper right, separated by the staircase line.

Do metals gain or lose electrons?
They lose them, forming positively charged ions (cations). Nonmetals gain or share electrons.

Is hydrogen a metal or a nonmetal?
A nonmetal, even though its position above Group 1 makes it look like an alkali metal.

What are metalloids?
Elements along the staircase line (B, Si, Ge, As, Sb, Te) with a mix of metal and nonmetal properties — often useful as semiconductors.

The takeaway

Metals are shiny, bendable conductors that lose electrons; nonmetals are dull, brittle insulators that gain or share them; and a thin band of metalloids sits in between. Use the staircase line to find them on the table, keep the exceptions (mercury, graphite, hydrogen) in mind, and you'll classify elements with confidence.

Coming next → [What Is an Ion? Cations, Anions, and Charges] — what happens when metals and nonmetals trade electrons. See also [The Periodic Table] and [Ionic vs Covalent Bonds].

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