CLASS 10 NOTES

CLASS 10 NOTES

PRASHANT KIRAD

SCIENCE

Metals & Non-Metals

Metal & Non-Metal

Metals:

Metals are a group of elements characterized by

their luster, conductivity (thermal and electrical),

malleability, and ductility. They typically have high

melting and boiling points and tend to lose

electrons to form positively charged ions (cations)

in chemical reactions. Common examples include

iron, copper, gold, and aluminum.

Physical properties of metals include:

1. Lustre: Metals exhibit a characteristic shine or luster when freshly

polished, attributed to their ability to reflect light.

2. Conductivity: Metals are excellent conductors of heat and electricity

due to the mobility of electrons in their atomic structure.

3. Malleability: Metals can be easily hammered or rolled into thin sheets

without breaking, displaying malleability.

4. Ductility: Metals can be drawn into thin wires without breaking,

demonstrating ductility.

5. High Melting and Boiling Points: Metals generally have high melting

and boiling points compared to nonmetals.

6. Solid State at Room Temperature: Most metals are solid at room

temperature, except for mercury, which is a liquid.

7. Density: Metals are typically dense materials, meaning they have a

high mass per unit volume.

8. Sonorous: Metals often produce a characteristic ringing sound when

struck, known as sonorousness.

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These properties collectively contribute to the wide range of practical

applications of metals in various industries, from construction to

electronics.

Chemical Properties of Metals:

1. Reaction with Oxygen:

● Metals react with oxygen to form metal oxides. The general equation

for this reaction is:

Metal+Oxygen→Metal Oxide

# Potassium and sodium metals are extremely reactive, undergoing vigorous

reactions with the oxygen in the air. In the presence of air, they can readily

catch fire and burn. To prevent these reactive metals from reacting with

oxygen, moisture, and carbon dioxide in the air, they are stored in kerosene oil.

This protective measure ensures that the metals remain stable and do not

undergo combustion when exposed to atmospheric conditions.

2. Reaction with Water:

● Some metals react with water to form metal hydroxides and release

hydrogen gas. The general equation is:

Metal+Water→Metal Hydroxide+Hydrogen

3. Reaction with Acids:

● Metals react with acids to produce salts and hydrogen gas. The

general equation is:

Metal+Acid→Salt+Hydrogen

4. Reaction with Salts:

● Metals can displace less reactive metals from their salts in solution.

The reactivity series helps predict such displacement reactions.

5. Reaction with Non-Metallic Elements:

● Metals can react with non-metallic elements to form compounds. For

example, metals react with sulfur to form metal sulfides.

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Explanation:

Reactivity Series of Metals:

The reactivity series ranks metals based on their tendency to undergo

displacement reactions. Higher-ranked metals can displace lower-ranked

ones from their compounds in solution. For example, zinc can displace

copper from copper sulfate. The series helps predict outcomes in chemical

reactions.

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Non-Metals:

Non-metals are elements that lack typical metallic properties. They are

generally poor conductors of heat and electricity and may exist in various

forms, such as solids, liquids, or gases. Non-metals often gain electrons in

chemical reactions and tend to form covalent bonds. Examples include

oxygen, nitrogen, carbon, and fluorine. They play essential roles in diverse

chemical and biological processes.

Physical Properties of Non-Metals:

States of Matter: Non-metals can exist in different states - solid, liquid,

or gas.

● Conductivity: Poor conductors of heat and electricity.

● Luster: Lack metallic luster, often appearing dull or matte.

● Malleability and Ductility: Not malleable or ductile; tend to be brittle.

● Density: Generally have lower density compared to metals.

● Melting and Boiling Points: Lower melting and boiling points than metals.

● Solubility: Some non-metals are sparingly soluble in water.

● Brittleness: Non-metals are often brittle in solid form.

● Color: Can exhibit various colors; for example, sulfur is yellow, and

iodine is purple.

Examples: Oxygen, nitrogen, sulfur, phosphorus.

Chemical properties of non-metals include:

● Combustibility: Some non-metals, like hydrogen and carbon, can

undergo combustion reactions.

● Reaction with Oxygen: Non-metals may react with oxygen to form

oxides. For example, sulfur reacts with oxygen to form sulfur dioxide.

● Acid-Base Reactions: Non-metals can react with bases to form salts.

For instance, sulfuric acid, a non-metal compound, reacts with sodium

hydroxide to form sodium sulfate and water.

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● Hydrogen Ion Formation: Non-metals may accept electrons to form

negatively charged ions (anions) in reactions with metals.

● Covalent Bonding: Non-metals form covalent bonds by sharing

electrons with non-metals.

● Reaction with Water: Some non-metals, such as sulfur and phosphorus,

react with water to produce acids.

● Reaction with Metals: Non-metals can displace less reactive metals

from their salts in solution, forming new compounds.

Metals & Non-Metals:

When metals interact with nonmetals, they combine to create ionic

compounds. Conversely, when nonmetals engage with other nonmetals, they

form covalent compounds.

Ionic Compounds:

1. Definition:

● Ionic compounds are chemical compounds composed of positively

charged ions (cations), usually derived from metals, and negatively

charged ions (anions), usually derived from nonmetals.

2. Formation:

● Ionic compounds are formed by transferring electrons from the

metal atom to the nonmetal atom. This transfer results in the

formation of ions with opposite charges.

3. Ionic Bonding:

● Ionic bonding is the electrostatic attraction between positively

charged ions (cations) and negatively charged ions (anions). This

attraction holds the ions together in a stable compound.

4. Examples:

● Common examples of ionic compounds include sodium chloride

(NaCl), potassium iodide (KI), and magnesium oxide (MgO).

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5. Properties:

● Ionic compounds generally have high melting and boiling points.

● They are usually solid at room temperature.

● They conduct electricity when dissolved in water or melted, as ions

are free to move.

Eg.

Properties of Ionic Compounds:

1. High Melting and Boiling Points:

● Ionic compounds typically have high melting and boiling points due to

strong electrostatic forces holding ions together in a

three-dimensional lattice.

2. Solubility in Water:

● Many ionic compounds are soluble in water because water molecules

surround and separate the ions, facilitating their movement.

3. Conductivity:

● Ionic compounds conduct electricity when dissolved in water or

molten, as ions become free to move and carry an electric charge.

4. Brittleness:

● Solid ionic compounds are often brittle because when force is applied,

layers of ions with like charges align, leading to repulsion and cleavage.

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Occurrence of Metals:

● Metals are predominantly obtained from the Earth's crust, which

serves as a major reservoir for these elements.

● Seawater contains soluble salts like sodium chloride and magnesium

chloride.

● The naturally occurring elements or compounds found in the Earth's

crust are referred to as minerals.

● Minerals that can be profitably processed to extract metals are

specifically termed ores.

Extraction of Metals from Ores:

Metallurgy Definition:

● Metallurgy is the systematic process of extracting metals in their pure

state from respective ores and refining them for practical use.

Extraction Techniques Based on Reactivity:

● Extraction methods vary depending on the position of metals in the

activity series.

Highly Reactive Metals:

● Metals with high reactivity, such as Potassium (K), Sodium (Na), Calcium

(Ca), and Magnesium (Mg), are typically extracted through electrolysis.

Their strong bonding with other components prevents reduction by

heating with carbon.

Moderately Reactive Metals:

● Moderately reactive metals like Zinc (Zn), Iron (Fe), and Lead (Pb) are

generally extracted through reduction processes using agents like coke

(C).

Less Reactive Metals:

● Less reactive metals, for instance, Copper (Cu) and Mercury (Hg), are

extracted from their oxides through heating alone, a method known as

self-reduction.

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Very Less Reactive Metals:

● Metals with very low reactivity, such as Silver (Ag), Gold (Au), and

Platinum (Pt), exist in nature in the metallic form and do not require

extraction processes.

The concentration of Ores:

Impurities and Gangue:

● Undesirable impurities, such as soil and sand, present in ores are

termed gangue or matrix.

Enrichment or Concentration:

● The process of removing gangue from the ore is known as

enrichment or concentration of the ore.

(I) Extraction of Metals of LOW Reactivity:

Self-Reduction:

Sulfide ores of less electropositive metals like Mercury (Hg), Lead (Pb),

and Copper (Cu) undergo self-reduction when heated in air. No external

reducing agent is used in this process.

Examples:

Cinnabar (HgS):

2HgS(Cinnabar)+3O2(g)+heat→2HgO(crude-metal)+2SO2(g)

2HgO(s)+heat→2Hg(l)+O2(g)

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Copper Glance (Cu₂S):

Cu2S(Copper-pyrite)+3O2(g)+heat→2Cu2O(s)+2SO2(g)

2Cu2O(s)+Cu2S(s)+heat→6Cu(crude metal)+SO2(g)

Galena (PbS):

2PbS(Galena)+3O2(g)+heat→2PbO(s)+2SO2(g)

PbS(s)+2PbO(s)→2Pb(crudemetal)+SO2(g)

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Corrosion:

Definition:

Corrosion refers to the gradual deterioration of a material, typically a

metal, due to the influence of moisture, air, or chemicals in the surrounding

environment. An example is the rusting of iron.

Prevention of Corrosion:

1. Coating with Paints, Oils, or Grease:

The application of paint, oil, or grease on metal surfaces forms a

protective barrier, preventing the ingress of air and moisture.

2. Alloying:

Alloying metals enhance corrosion resistance. For instance, stainless

steel is an alloy that exhibits increased resistance to corrosion.

3. Galvanization:

Galvanization involves coating iron articles with molten zinc. Zinc forms

a protective layer, serving as a barrier against corrosion.

4. Electroplating:

Electroplating, achieved through an electric current, involves coating

one metal with another. This method not only protects against

corrosion but also enhances the aesthetic appearance. Examples include

silver plating and nickel plating.

5. Sacrificial Protection:

Magnesium, being more reactive than iron, can act as a sacrificial layer.

When coated on iron or steel articles, magnesium serves as the

cathode, undergoing a sacrificial reaction instead of the iron, thus

protecting the articles.

Alloys:

Definition:

Alloys are uniform mixtures of metals with either other metals or

nonmetals. The formation of alloys results in improved properties,

including increased hardness, tensile strength, and corrosion resistance.

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Examples of Alloys:

1. Brass:

- Brass is an alloy composed of copper and zinc.

2. Bronze:

- Bronze is an alloy formed by combining copper and tin.

#Top Seven Questions:

1) Explain why calcium metal after reacting with water starts floating on its

surface. Write the chemical equation for the reaction. Name one more metal

that starts floating after some time when immersed in water.

Sol���o�: When calcium metal reacts with water, it produces hydrogen gas and

calcium hydroxide. The hydrogen gas bubbles stick to the surface of the

calcium, creating buoyancy, causing calcium to float on the water's surface.

The chemical equation for the reaction is:

Ca (s)+2H2O (l)→Ca(OH)2(aq)+H2(g)

Another metal that starts floating after some time when immersed in water is

sodium.

2 (a) (i) Write two properties of gold that make it the most suitable metal for

ornaments.

(ii) Name two metals which are the best conductors of heat.

(iii) Name two metals that melt when you keep them on your palm.

(iv) Explain the formation of the ionic compound CaO with an electron-dot

structure. Atomic numbers of calcium and oxygen are 20 and 8 respectively.

[5M, 2020]

Sol���o�: (i). The property of gold used in making ornaments is ductility and

luster.

(ii). Silver are copper are the best conductors of heat.

(iii). Gallium and cesium are the metals that melt when kept on the palm.

(iv) Atomic no. of Ca - 20, Electronic Configuration 2,8,8,2 Atomic no. of O - 8

Electronic Configuration - 2,6

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3. (a)Carbon cannot be used as a reducing agent to obtain Mg from MgO. Why?

(b) How is sodium obtained from molten sodium chloride? Give an equation of

the reactions.

(c) How is copper obtained from its sulfide ore? Give equations of the

reactions.

Sol���o�: (a) Carbon and MgO:

- Carbon can't reduce MgO; Mg is more reactive.

(b) Sodium from Molten NaCl:

- Na obtained from molten NaCl by electrolysis:

2NaCl (l)→2Na (l)+Cl2(g)

(c) Copper from Sulfide Ore:

- Copper from CuFeS₂ by smelting:

CuFeS2(s)+O2(g)→Cu (l)+FeO (s)+SO2(g)

4. The way, metals like sodium, magnesium, and iron react with air and water

is an indication of their relative positions in the ‘reactivity series’. Is this

statement true? Justify your answer with examples.

Sol���o�: Yes, the statement is true. The reactivity series ranks metals based on

their tendency to undergo reactions. Metals like sodium, which reacts

vigorously with both air and water, magnesium, which burns in air and reacts

with water, and iron, which reacts with oxygen and steam, demonstrate the

correlation between their reactivity and their positions in the reactivity

series.

5. A non-metal X exists in two different forms, Y and Z. Y is the hardest

natural substance, whereas Z is a good conductor of electricity. Identify X, Y,

and Z.

Sol���o�: X is carbon. Diamond and graphite are allotropes of carbon. Diamond is

the hardest natural substance, and hence Y is diamond. Graphite is a good

conductor of electricity, and hence Z is graphite.

6. What are the constituents of solder alloy? Which property of solder makes

it suitable for welding electrical wires?

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Sol���o�: Constituents of Solder Alloy:

- Typically, tin and lead or lead-free alternatives with elements like silver,

copper, or antimony.

Property Suitable for Welding Electrical Wires:

- Low melting point of solder (below 450°F or 232°C), enabling easy melting

and secure bonding without damaging the electrical wires.

7. A metal that exists as a liquid at room temperature is obtained by heating

its sulfide in the presence of air. Identify the metal and its ore and give the

reaction involved.

Sol���o� Mercury is the only metal that exists as a liquid at room temperature.

It can be obtained by heating cinnabar (HgS), the sulfide ore of mercury. We

can get metals low in activity series by heating or reducing their sulfides or

oxides.

The reactions are as follows

2 HgS + 3 O2 → 2 HgO + 2 SO2

2 HgO → 2 Hg + O2

# Compentancy Based Question:

1) Ores mined from the earth are usually contaminated with large amounts of

impurities such as soil, sand, etc., called gangue. The impurities must be

removed from the ore before the extraction of the metal. The processes

Several steps are involved in the extraction of pure metal from ores. Metals

and non-metals used for removing the gangue from the ore are based on the

differences between the physical or chemical properties of the gangue and

the ore. Different separation techniques are accordingly employed.

1. What is gangue in the context of ores?

2. Why remove gangue before extracting metals?

reactions, the metals have been arranged in the decreasing order of their reactivities. This arrangement is known as activity series or reactivity series of metals. The basis of reactivity is the tendency of metals to lose electrons. If a metal can lose electrons easily to form positive ions, it will react readily with other substances. Therefore, it will be a reactive metal. On the other hand, if a meal loses electrons less rapidly to form a positive ion, it will react slowly with other substances.

Therefore, such a metal will be less reactive.

1. Based on the reactivity of different metals with oxygen, water and acids as well as displacement

1. Which of the following metal is less reactive than hydrogen?

A.Copper B.Zinc C.Magnesium D. Lead

A. Na>Mg>Al>Cu B. Mg>Na>Al>Cu C. Na>Mg>Cu>Al D. Mg > Al > Na > Cu

2. Which of the following represents the correct order of reactivity for the given metals?

the nitrogen oxides (N,O, NO, NO2). But _____________ and _____________ react with very dilute HNO3 to evolve H2 gas.

A. Pb, Cu B. Na, K C. Mg, Mn D. Al, Zn

strong oxidising agent. It oxidises the H, produced to water and itself gets reduced to any of

3. Hydrogen gas is not evolved when a metal reacts with nitric acid. It is because HNO, is a

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3. How are separation techniques for gangue removal determined in

metal extraction?

Sol���o�

1. Gangue refers to impurities like soil and sand present in ores.

2. Removing gangue is essential to ensure the purity of the extracted

metal and prevent interference with the extraction process.

3. Separation techniques are based on differences in physical or

chemical properties between gangue and ore components, employing

methods like froth flotation and magnetic separation.

1. The metals in the middle of the activity series such as iron, zinc, lead,

copper, etc., are moderately reactive. These are usually present as sulfides

or carbonates in nature. It is easier to obtain a metal from its oxide, as

compared to its sulphides and carbonates. Therefore, before reduction,

the metal sulfides and carbonates must be converted into metal oxides.

The sulfide ores are converted into oxides by heating strongly in the

presence of excess air. This process is known as roasting. The carbonate

ores are changed into oxides by heating strongly in limited air. This

process is known as calcination.

1. Which metals are considered moderately reactive and typically found in the middle

of the activity series?

2. Why is it easier to obtain metal from its oxide rather than its sulfides or

carbonates?

3. What is the process used to convert metal sulfides into oxides, and what is it

called?

Sol���o�

1. Metals such as iron, zinc, lead, copper, etc., are considered moderately

reactive and are located in the middle of the activity series.

2. Obtaining a metal from its oxide is easier because metal oxides are

generally more readily reducible than metal sulphides or carbonates.

3. The process used to convert metal sulphides into oxides is called

"roasting," which involves heating strongly in the presence of excess air.

A. Zinc B. Magnesium C. Sodium D. Copper

4. Which of the following metals reacts vigorously with oxygen?

loses the valence electrons while non-metal atom accepts these electrons. By losing electrons, metal

generally solid and exist in the form of crystal. They have high melting and boiling points. atoms change to cations and by accepting electrons, non-metals form anions. Ionic compounds are

bond is the type of chemical bond in which two oppositely charged ions are held through electrostatic

non-metal atoms need electrons in their valence shell to attain noble gas configuration. The metal atom

2. An ionic compound is a chemical compound in which ions are held together by ionic bonds. An ionic

forces. We know that metal atoms have loosely bound valence electrons in their valence shell and

1. Which of the following can change to a cation?

A. Fluorine B. Oxygen C. Potassium D. Neon

2. Which of the following can change to an anion?

A. Iodine B. Magnesium C. Calcium D. Xenon

3. Ionic compounds are soluble in _____________.

A. Kerosene B. Petrol C. Water D. None of these

III. They conduct electricity in molten state.

A. I only B. II only C. III only D. II and III only

4. Which of the following statements is correct about ionic compounds?

II. They conduct electricity in solutions.

I. They conduct electricity in solid state.

5.Select the incorrect statement.

A. Ionic compounds are generally brittle B. Ions are the fundamental units of ionic compounds C. Formation of ionic bonds involve sharing of electrons D.NaCl is an ionic compound.

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