Properties of Metals and Nonmetals

Metals are considered to be solids, but mercury is a metal that occurs in the liquid state.

Elements can be classified into metals, nonmetals, and metalloids.

The classification solely depends on their nature and the properties they exhibit. The differences in their properties is clearly visible from their placement in the periodic table.

While metals are placed on the left-hand side, nonmetals are placed on the right-hand side of the periodic table.

The properties of any element are defined by the number of electrons present in their valence shell. In case of metals, the outer shell contains 1-3 electrons, whereas the outer shell of nonmetals contains 4-8 electrons. Their configuration imparts them the chemical and physical properties they possess. Let us see some characteristics of both of them.

♦ They are opaque.

♦ They are capable of producing a bell-like sound when hit.

♦ On undergoing any chemical reaction, they lose electrons and form positively charged cations.

♦ They are electropositive and considered to be good reducing agents.

♦ Metals are known to form ionic compounds.

♦ On reaction with dilute acids, they release hydrogen.

♦ The chloride and hydride compounds formed by metals are in the solid state.

♦ They like to react with nonmetals.

♦ They form oxides that are basic in nature. Consider a reaction of magnesium with oxygen.

Mg + O₂ ➜ MgO
Magnesium + Oxygen ➜ Magnesium oxide

● Magnesium
● Potassium
● Aluminum
● Iron
● Silver
● Sodium

✦ They are either solid, liquid, or gaseous at room temperature.

✦ They possess no luster and are dull. They cannot be polished.

✦ They break if tried to flatten into thin sheets, i.e., they are not malleable, but brittle.

✦ They cannot be drawn into thin wires as they break apart easily.

✦ They do not conduct electricity or heat. Thus, they are termed insulators.

✦ They are lighter in weight.

✦ They have a low tensile strength.

✦ They are transparent.

✦ They have a very low density because the atoms in their molecular structure are loosely packed.

✦ They do not produce any sound when hit.

✦ They have extremely low melting and boiling points.

✦ On undergoing any chemical reaction, nonmetals gain electrons and form negatively charged anions.

✦ They are electronegative and considered as good oxidizing agents.

✦ Nonmetals are known to form covalent compounds.

✦ They are not reactive to dilute acids.

✦ The chlorides and hydrides formed are in the liquid or gaseous state.

✦ They like to react with metals.

✦ They form oxides that are acidic in nature. Consider a reaction of sulfur with oxygen.

S + O₂ ➜ SO₂
Sulfur + Oxygen ➜ Sulfur dioxide

Besides the metals and nonmetals, the periodic table consists of certain elements having properties of metals as well as nonmetals. These elements are called metalloids.