Properties of Metals and NonMetals (original) (raw)

Last Updated : 6 Apr, 2026

Metals and non-metals exhibit distinct physical and chemical properties, which depend on their position in the periodic table. These differences arise due to variations in their atomic structure, bonding, and electron configuration.

Physical properties include characteristics like conductivity, malleability, ductility, density, and physical state, while chemical properties involve their reactions with oxygen, water, acids, and other substances, along with their tendency to lose or gain electrons.

Metals show a wide range of properties based on their physical strength and chemical reactivity, which makes them highly useful in daily life and industrial applications.

A. Physical Properties

**1. Lustrous (Shiny)
Metals have a shiny surface due to their ability to reflect light, known as "metallic luster." This property makes metals like gold and silver suitable for jewelry.

**2. Malleability
Metals can be hammered into thin sheets without breaking due to strong metallic bonding.
_Example: Aluminium foil

**3. Ductility
Metals can be drawn into thin wires, which is why they are widely used in electrical wiring.
_Example: Copper wires

**4. Sonorous Nature
Metals produce a ringing sound when struck, hence used in bells and musical instruments.

**5. Good Conductors of Heat and Electricity
Due to the presence of free electrons, metals conduct heat and electricity efficiently.

**6. High Melting and Boiling Points
Strong metallic bonds require high energy to break, resulting in high melting and boiling points.
Exceptions: Mercury is liquid at room temperature (very low melting point), while gallium and cesium melt at relatively low temperatures.

**7. Generally Solid at Room Temperature
Most metals are solid due to strong forces of attraction.
Exception: Mercury

B. Chemical Properties

**1. Reaction with Oxygen

Metals react with oxygen to form metal oxides, which are generally basic in nature because they form bases when dissolved in water.

2Mg + O_2 \rightarrow 2MgO

Some metal oxides like Al₂O₃ and ZnO are amphoteric, meaning they can react with both acids and bases. In some cases, a thin oxide layer (like in aluminium) prevents further corrosion.

**2. Reaction with Water

Metals react with water at different rates depending on their reactivity:

2Na + 2H_2O \rightarrow 2NaOH + H_2 + \text{Heat}

These reactions show that metals tend to displace hydrogen from water, indicating their reactivity.

**3. Reaction with Acids

Metals react with dilute acids to form salt and hydrogen gas. This is a common test for metals.

Zn + 2HCl \rightarrow ZnCl_2 + H_2

Metals above hydrogen in the reactivity series can displace hydrogen from acids, while those below cannot.

**4. Displacement Reaction

A more reactive metal can displace a less reactive metal from its compound in solution. This is known as a single displacement reaction.

Zn + CuSO_4 \rightarrow ZnSO_4 + Cu

This property is useful in metal extraction and electrochemical processes.

**5. Formation of Ionic Compounds

Metals tend to lose electrons easily due to low ionization energy and form positive ions (cations).

Na \rightarrow Na^+ + e^-

These cations combine with anions to form ionic compounds, which are usually hard, crystalline, and have high melting points.

Non-metals show properties opposite to metals and are mostly found on the right side of the periodic table. They are essential in biological, environmental, and chemical processes.

A. Physical Properties

**1. Non-Lustrous
Non-metals generally have a dull appearance as they do not reflect light.

**2. Brittle Nature
They are brittle and break easily when force is applied, so they cannot be shaped like metals.

**3. Poor Conductors of Heat and Electricity
Due to the absence of free electrons, non-metals are poor conductors.
Exception: Graphite conducts electricity due to delocalized electrons.

**4. Low Melting and Boiling Points
Non-metals have weak intermolecular forces, so they melt and boil at lower temperatures.

**5. Exist in All Three States

B. Chemical Properties

**1. Reaction with Oxygen
Non-metals react with oxygen to form non-metal oxides, which are generally acidic in nature.

CO_2 + H_2O \rightarrow H_2CO_3

These oxides dissolve in water to form acids, showing their acidic character. Some oxides (like CO) are neutral.

**2. Reaction with Hydrogen

Non-metals react with hydrogen to form covalent compounds, as they share electrons instead of transferring them.

H_2 + Cl_2 \rightarrow 2HCl

These compounds are usually molecular and have low melting and boiling points.

**3. Gain of Electrons

Non-metals tend to gain electrons due to high electronegativity, forming negative ions (anions).

Cl + e^- \rightarrow Cl^-

This tendency makes them strong oxidizing agents.

**4. Reaction with Metals

Non-metals react with metals to form ionic compounds.

Example: 2Na + Cl_2 \rightarrow 2NaCl

Here, metal transfers electrons to non-metal, forming an ionic bond.

**5. Nature of Bonding

Non-metals usually form covalent bonds by sharing electrons with other non-metals. These compounds are generally poor conductors and have low melting points.