Where they are on the periodic table
Metal: 84Metalloid: 6Nonmetal: 20Properties unknown: 8
Our periodic table sorts 118 elements into categories. Of these, 84 are metals, 20 are nonmetals, and 6 are metalloids. The other 8 elements are very heavy and have been made only a few atoms at a time. Their properties are not fully known.
Difference between metals and nonmetals
| Property | Metals | Nonmetals |
|---|---|---|
| Appearance | Shiny | Usually dull |
| Electrical and thermal conductivity | Good | Usually poor |
| Shape | Malleable and ductile: can be hammered flat and drawn into wire | Brittle as solids |
| State at room temperature | Usually solid | Solid, liquid, or gas |
| In reactions | Lose electrons and form cations | Gain electrons and form anions, or form shared electron pairs |
| Oxides | Usually basic | Usually acidic |
There are exceptions to these rules. Mercury is a metal that is liquid at room temperature. Bromine is a liquid nonmetal. Graphite, a form of carbon, conducts electricity.
What are metalloids?
Metalloids are elements with properties between those of metals and nonmetals. Our classification includes six of them: boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), and tellurium (Te). Silicon and germanium are semiconductors, so they are used in electronic devices.
How do you tell if an element is a metal?
- Find the element on the periodic table.
- If it is to the left of the staircase line from boron to tellurium, it is usually a metal.
- If it is in the upper right, it is a nonmetal.
- If it is on the staircase line, it may be a metalloid, so check its category.
Seven of the first 20 elements are metals: Li, Be, Na, Mg, Al, K, Ca. You can find the rest in the table of the first 20 elements.
Learn to tell metals from nonmetals in the Nalukh chem app
In the periodic table, each element is color-coded by its category. The periodic table is free, and no sign-up is required.
Try it in the simulator
In the "Metals and Nonmetals" simulator in the Nalukh chem app, you test the properties of substances and learn to tell whether each one is a metal.
