Metals and Non-metals

Q: Electricity is simply the flow of charged particles. Ionic compounds like $\mathrm{NaCl}$ (table salt) are made entirely of charged ions ($\mathrm{Na^+}$ and $\mathrm{Cl^-}$). So why don’t they conduct electricity when solid? In the solid state, these ions are locked tightly in a rigid crystal lattice by strong electrostatic forces. They are trapped and cannot move. However, when you melt the salt or dissolve it in water, the lattice breaks apart. The ions are now free to swim around and carry the electric current!

Setup: – Anode (Positive): A thick block of impure Copper. – Cathode (Negative): A thin strip of pure Copper. – Electrolyte: An acidified solution of Copper Sulphate ($\mathrm{CuSO_4}$). Impurities: On passing current, pure copper from the anode dissolves into the electrolyte, and an equivalent amount deposits on the cathode. Soluble impurities go into the solution, whereas the insoluble impurities settle down at the bottom of the anode and are known as Anode Mud.

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Home Concept Boosters CBSE CBSE Class 10 Science Metals & Non-metals

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How to Use This Page

Read each concept carefully, then check the formula, common mistake, and exam tip before moving to the next. This page completely covers Metals and Non-metals for CBSE Class 10 Science, bridging the gap between basic chemical reactions and industrial metallurgy.

Key Concepts

Class 10 · Science · Chemistry

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Properties, Reactivity, and Extraction

Class 10 · Ch 3

Physical Properties Definition

Metals: Malleable (beaten into sheets), Ductile (drawn into wires), Lustrous, Sonorous, good conductors of heat and electricity.
Non-metals: Brittle, non-lustrous, poor conductors (Insulators).

$$\text{Exceptions: Mercury (liquid metal), Graphite (conducts electricity)}$$

Amphoteric Oxides Formula

Most metal oxides are basic, but some metal oxides (like Aluminum oxide and Zinc oxide) show both acidic and basic behavior. They react with both acids and bases to produce salt and water.

$$\mathrm{Al_2O_3 + 6HCl \rightarrow 2AlCl_3 + 3H_2O}$$

$$\mathrm{Al_2O_3 + 2NaOH \rightarrow 2NaAlO_2 + H_2O}$$

Reaction with Water Concept

Different metals react with water under different conditions.
Cold Water: K, Na, Ca.
Hot Water: Mg.
Steam: Al, Zn, Fe.
No Reaction: Pb, Cu, Ag, Au.

$$\mathrm{Metal + Steam \rightarrow Metal~Oxide + H_2(g)}$$

The Reactivity Series Scale

A list of metals arranged in the order of their decreasing activities. A more reactive metal can displace a less reactive metal from its salt solution.

$$\mathrm{K > Na > Ca > Mg > Al > Zn > Fe > Pb > [H] > Cu > Hg > Ag > Au}$$

Formation of Ionic Bonds Concept

Metals lose electrons to achieve a noble gas configuration (forming positive cations). Non-metals gain electrons (forming negative anions). The strong electrostatic force of attraction between them forms an Electrovalent (Ionic) Bond.

$$\mathrm{Na \rightarrow Na^+ + e^- \quad | \quad Cl + e^- \rightarrow Cl^-}$$

Properties of Ionic Compounds Rule

They are hard, brittle crystalline solids with very high melting and boiling points (due to strong inter-ionic forces). They conduct electricity only in molten or aqueous state, not in solid state.

$$\text{Solid State } \rightarrow \text{ Insulator } | \text{ Molten/Aqueous State } \rightarrow \text{ Conductor}$$

Roasting and Calcination Process

Methods to convert ores into metal oxides for easier extraction.
Roasting: Heating Sulphide ores strongly in the presence of excess air.
Calcination: Heating Carbonate ores strongly in limited air.

$$\text{Roasting: } \mathrm{2ZnS + 3O_2 \xrightarrow{Heat} 2ZnO + 2SO_2}$$

$$\text{Calcination: } \mathrm{ZnCO_3 \xrightarrow{Heat} ZnO + CO_2}$$

Thermite Reaction Formula

A highly exothermic displacement reaction between a metal oxide (like Iron(III) oxide) and Aluminum powder. The heat produced is so massive that the metal is produced in a molten state. Used to join railway tracks.

$$\mathrm{Fe_2O_3_{(s)} + 2Al_{(s)} \rightarrow 2Fe_{(l)} + Al_2O_3_{(s)} + Heat}$$

Electrolytic Refining Process

The most widely used method for refining impure metals (like Cu, Zn, Ag). The impure metal is made the Anode, a thin strip of pure metal is the Cathode, and the electrolyte is a salt solution of the metal.

$$\text{Pure metal deposits at Cathode } (-) \text{ | Impurities settle as Anode Mud}$$

Alloys Definition

A homogeneous mixture of two or more metals (or a metal and a non-metal). Alloying alters properties like strength, conductivity, and corrosion resistance.

$$\text{Brass } (\mathrm{Cu + Zn}) \quad | \quad \text{Bronze } (\mathrm{Cu + Sn}) \quad | \quad \text{Solder } (\mathrm{Pb + Sn})$$

Concept Deep Dive

The Magic of Aqua Regia

Dissolving the undissolvable

Core Concept

Gold and Platinum are “noble metals.” They reside at the very bottom of the reactivity series and do not react with strong acids like concentrated $\mathrm{HCl}$ or concentrated $\mathrm{HNO_3}$ individually.

However, if you mix concentrated Hydrochloric acid ($\mathrm{HCl}$) and concentrated Nitric acid ($\mathrm{HNO_3}$) in a strict 3:1 ratio, you create a fuming, highly corrosive liquid called Aqua Regia (Royal Water). Together, they can dissolve Gold! This mixture is often used by goldsmiths to clean or alter gold jewelry.

Why don’t Solid Ionic Compounds Conduct Electricity?

The prison of the crystal lattice

Crucial Understanding

Electricity is simply the flow of charged particles. Ionic compounds like $\mathrm{NaCl}$ (table salt) are made entirely of charged ions ($\mathrm{Na^+}$ and $\mathrm{Cl^-}$). So why don’t they conduct electricity when solid?

In the solid state, these ions are locked tightly in a rigid crystal lattice by strong electrostatic forces. They are trapped and cannot move. However, when you melt the salt or dissolve it in water, the lattice breaks apart. The ions are now free to swim around and carry the electric current!

Compare & Contrast

✗ Roasting

Used for Sulphide ($\mathrm{S^{2-}}$) ores (e.g., $\mathrm{ZnS}$).
Heated strongly in the presence of excess air/oxygen.
Produces $\mathrm{SO_2}$ gas as a byproduct.
$\mathrm{2ZnS + 3O_2 \rightarrow 2ZnO + 2SO_2}$

✓ Calcination

Used for Carbonate ($\mathrm{CO_3^{2-}}$) ores (e.g., $\mathrm{ZnCO_3}$).
Heated strongly in the absence or limited supply of air.
Produces $\mathrm{CO_2}$ gas as a byproduct.
$\mathrm{ZnCO_3 \rightarrow ZnO + CO_2}$

Common Mistakes to Avoid

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Mistake 1

Confusing the Anode and Cathode in Refining: In the electrolytic refining of copper, students often mix up where the pure and impure metals go.
Anode = Acting bad (Impure metal).
Cathode = Clean (Pure metal).
The impurities drop below the Anode to form “Anode Mud”.

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Mistake 2

Assuming all metals produce Hydrogen gas with Nitric Acid: Nitric acid ($\mathrm{HNO_3}$) is a very strong oxidizing agent. When most metals react with it, it oxidizes the produced $\mathrm{H_2}$ into water ($\mathrm{H_2O}$) and reduces itself to nitrogen oxides ($\mathrm{NO_2, NO}$). Exception: Only Magnesium ($\mathrm{Mg}$) and Manganese ($\mathrm{Mn}$) react with very dilute $\mathrm{HNO_3}$ to evolve $\mathrm{H_2}$ gas!

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Mistake 3

Incorrect Electron Dot Structures: When showing the formation of ionic bonds (like $\mathrm{MgCl_2}$), students often draw sharing circles like a covalent bond. Ionic bonds are formed by the complete transfer of electrons. Use arrows to show the electron leaving the metal and moving to the non-metal, and use brackets with charges $[\mathrm{Mg}]^{2+} [\mathrm{Cl}]^-_2$ for the final product.

Exam Tips

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Tip 1

The “Floating Metal” Question: Calcium and Magnesium start floating when they react with water. Why? Because the bubbles of hydrogen gas formed during the reaction stick to the surface of the metal, making it buoyant.

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Tip 2

Exceptions are highly tested! Examiners love to test your knowledge of exceptions. Remember:
– Iodine is a non-metal but has lustre.
– Diamond is a non-metal but is the hardest natural substance.
– Gallium and Cesium are metals but have incredibly low melting points (they melt on your palm).

Expected Exam Questions

Board Pattern Questions

Class 10 · Science · CBSE Exam

Class 10 · Chemistry

What are amphoteric oxides? Give two examples of amphoteric oxides. Write chemical equations to justify your answer. [3 marks]

Answer Oxides showing both acidic and basic behavior. E.g., $\mathrm{Al_2O_3}$ and $\mathrm{ZnO}$. 📝

Explanation

Amphoteric oxides are metal oxides that react with both acids as well as bases to produce salt and water, showing both acidic and basic nature.
Examples: Aluminum Oxide ($\mathrm{Al_2O_3}$) and Zinc Oxide ($\mathrm{ZnO}$).
Reaction with Acid: $\mathrm{Al_2O_3 + 6HCl \rightarrow 2AlCl_3 + 3H_2O}$
Reaction with Base: $\mathrm{Al_2O_3 + 2NaOH \rightarrow 2NaAlO_2 + H_2O}$ (Sodium aluminate)

Draw a labeled diagram of the experimental setup for the electrolytic refining of copper. State what happens to the impurities present in the impure copper. [3 marks]

Answer Impure Anode, Pure Cathode, Acidified $\mathrm{CuSO_4}$ solution. 📝

Explanation

Setup:
– Anode (Positive): A thick block of impure Copper.
– Cathode (Negative): A thin strip of pure Copper.
– Electrolyte: An acidified solution of Copper Sulphate ($\mathrm{CuSO_4}$).
Impurities: On passing current, pure copper from the anode dissolves into the electrolyte, and an equivalent amount deposits on the cathode. Soluble impurities go into the solution, whereas the insoluble impurities settle down at the bottom of the anode and are known as Anode Mud.

You are given solutions of $\mathrm{FeSO_4}$, $\mathrm{ZnSO_4}$, $\mathrm{CuSO_4}$, and $\mathrm{AgNO_3}$. A student drops a strip of Zinc metal into each test tube. In which test tubes will a reaction take place? Justify your answer based on the Reactivity Series. [3 marks]

Answer Reactions occur in $\mathrm{FeSO_4}$, $\mathrm{CuSO_4}$, and $\mathrm{AgNO_3}$. No reaction in $\mathrm{ZnSO_4}$. 📝

Explanation

According to the Reactivity Series, a more reactive metal can displace a less reactive metal from its salt solution.
– The reactivity order is: $\mathrm{Zn > Fe > Cu > Ag}$.
– Since Zinc ($\mathrm{Zn}$) is more reactive than Iron ($\mathrm{Fe}$), Copper ($\mathrm{Cu}$), and Silver ($\mathrm{Ag}$), it will displace them from their respective salt solutions ($\mathrm{FeSO_4}$, $\mathrm{CuSO_4}$, $\mathrm{AgNO_3}$).
– Zinc cannot displace itself, so there is no reaction in the $\mathrm{ZnSO_4}$ solution.

Concept Map

Metals and Non-metals connects to →

Chemistry of Elements

Carbon and its Compounds (Covalent bonds vs Ionic bonds)

Periodic Classification (Position of metals/non-metals)

Electricity (Conductors and Insulators)

Metals and Non-metals – Concept Booster | Class 10 Science CBSE

Key Concepts

Metals and Non-metals