Metals and non-metals Class 10

 

 Metals and non-metals

Metals and non-metals are fundamental classifications in chemistry, distinguishing elements based on their physical and chemical properties. Metals are characterized by their luster, malleability, conductivity (both thermal and electrical), and typically solid state at room temperature, with exceptions like mercury. They are also known for forming positively charged ions (cations) by losing electrons.

On the other hand, non-metals exhibit a wide range of properties contrasting metals. They are generally brittle when solid and lack metallic luster. Non-metals tend to be poor conductors of heat and electricity, though exceptions like graphite exist. They typically form negatively charged ions (anions) by gaining electrons.

The periodic table serves as a visual representation of these elements, organized based on increasing atomic number and grouped into metals, non-metals, and metalloids (elements that exhibit properties of both). Metals dominate the left and center of the table, while non-metals are primarily found on the upper right side.

The interactions between metals and non-metals are crucial in chemical reactions, influencing the formation of compounds. Ionic bonding, where electrons are transferred from metals to non-metals, and covalent bonding, where electrons are shared between non-metals, are key examples of these interactions.

Understanding metals and non-metals is essential not only for academic study but also for practical applications across industries such as manufacturing, electronics, and construction. Their diverse properties and behavior underlie their widespread use and contribute significantly to the advancements in materials science and technology.

Metals possess a distinctive set of physical properties that distinguish them from other materials. These properties contribute to their utility across various industries and everyday applications.

1. Luster: Metals have a characteristic metallic luster, often described as shiny or reflective. This property arises from the ability of metals to reflect light uniformly due to the presence of free electrons on their surface.

2. Malleability and Ductility: One of the most defining characteristics of metals is their ability to be hammered or rolled into thin sheets (malleability) and drawn into wires (ductility) without breaking. This property is attributed to the metallic bonding, where layers of atoms can slide over each other without disintegration.

3. Conductivity: Metals are excellent conductors of electricity and heat. This conductivity stems from the free electrons within the metal lattice structure. When a voltage or heat is applied, these free electrons can move easily through the metal, transferring electrical current or thermal energy efficiently.

4. Density: Metals generally have high densities compared to non-metals, which contribute to their weight and strength. Dense metals like gold and platinum are valued for their heft and durability in jewelry and industrial applications.

5. Melting and Boiling Points: Metals typically have high melting and boiling points compared to non-metals. This characteristic makes them suitable for applications requiring high-temperature resistance, such as in engines, industrial furnaces, and aerospace materials.

6. Opacity: Most metals are opaque to visible light due to their ability to absorb and reflect light. This property contributes to their use in manufacturing and construction, where opacity is often desired for structural integrity and aesthetic appeal.

7. Tensile Strength: Metals exhibit high tensile strength, meaning they can withstand pulling forces without breaking. This property is crucial in structural applications, where metals are used in beams, bridges, and other load-bearing structures.

Understanding these physical properties of metals is essential for their selection and application in various fields, ranging from engineering and construction to electronics and medicine. Their unique combination of strength, conductivity, and durability continues to drive innovations in materials science and technology.

Non-metals exhibit a diverse range of physical properties that differentiate them from metals. These properties play a crucial role in their applications across various industries and scientific fields.

1. Luster: Non-metals generally lack metallic luster and appear dull or earthy in texture. For example, sulfur and graphite are non-metals that do not exhibit shiny surfaces.

2. Brittleness: Non-metals are often brittle in solid form, meaning they break or shatter when subjected to stress rather than deforming. For instance, sulfur and phosphorus are brittle non-metals.

3. Conductivity: Non-metals are generally poor conductors of electricity and heat. This property arises because non-metals do not have free electrons that can move easily to conduct electricity. Examples include sulfur, carbon (in its most common form as graphite), and nitrogen.

4. Density: Non-metals have lower densities compared to metals. This characteristic contributes to their lightweight nature. For example, hydrogen and helium are non-metals with very low densities.

5. Melting and Boiling Points: Non-metals typically have lower melting and boiling points compared to metals. For instance, sulfur melts at a relatively low temperature of 115.21°C and boils at 444.6°C, whereas carbon sublimes (converts directly from solid to gas) at 3915°C under standard conditions.

6. Opacity and Transparency: Non-metals vary in their transparency to light. Some non-metals, like sulfur and phosphorus, are opaque, while others, such as oxygen and hydrogen, are transparent gases.

7. Tensile Strength: Non-metals generally have lower tensile strength compared to metals. They are less capable of withstanding pulling forces without breaking. For example, carbon in its diamond form is one of the hardest substances known but lacks the ductility and tensile strength of metals.

Understanding these physical properties of non-metals is essential for their use in various applications, including electronics, agriculture, pharmaceuticals, and environmental sciences. Their unique combination of properties makes non-metals indispensable in materials science and everyday technologies.

Chemical properties of metals are fundamental characteristics that define their behavior in chemical reactions and interactions with other substances. These properties include their ability to form positive ions (cations), react with acids and oxygen, and undergo corrosion.

1. Formation of Positive Ions (Cations):

   Metals have a tendency to lose electrons from their outer shells to achieve a stable electron configuration, typically the noble gas configuration. This results in the formation of positively charged ions known as cations. The reaction for this process can be represented as:

   \[ \text{Metal} \rightarrow \text{Metal ion} + \text{Electrons} \]

 

   Example: Sodium (Na) losing one electron to form the sodium ion (Na⁺):

 

   \[ \text{Na} \rightarrow \text{Na}^+ + \text{e}^- \]

2. Reaction with Acids:

   Salt and hydrogen gas are produced when Metals react with acids . The general equation for this reaction is:

   \[ \text{Metal} + \text{Acid} \rightarrow \text{Salt} + \text{Hydrogen gas} \]

   Example: Zinc (Zn) reacting with hydrochloric acid (HCl) to produce zinc chloride (ZnCl₂) and hydrogen gas (H₂):

   \[ \text{Zn} + 2\text{HCl} \rightarrow \text{ZnCl}_2 + \text{H}_2 \]

 

3. Reaction with Oxygen (Oxidation):

   Metals react with oxygen to form metal oxides. The general equation for this reaction is:

   \[ \text{Metal} + \text{Oxygen} \rightarrow \text{Metal Oxide} \]

   Example: Iron (Fe) reacting with oxygen (O₂) to form iron oxide (Fe₂O₃):

 

   \[ 4\text{Fe} + 3\text{O}_2 \rightarrow 2\text{Fe}_2\text{O}_3 \]

 

4. Corrosion:

   Metals can undergo corrosion, which is a gradual destruction of metals by chemical reaction with substances in the environment, such as oxygen and moisture. The corrosion of iron (rusting) is a well-known example:

 

   \[ \text{4Fe} + \text{3O}_2 + \text{2H}_2\text{O} \rightarrow \text{2Fe}_2\text{O}_3 \cdot \text{2H}_2\text{O} \]

 

   This equation shows the formation of hydrated iron oxide (rust) from iron, oxygen, and water.

5. Displacement Reactions:

   Metals can displace less reactive metals from their salts in aqueous solutions, a process known as a displacement reaction. The general equation for a displacement reaction is:

   \[ \text{Metal A} + \text{Salt of Metal B} \rightarrow \text{Metal B} + \text{Salt of Metal A} \]

 

   Example: Zinc (Zn) displacing copper (Cu) from copper sulfate (CuSO₄) solution:

   \[ \text{Zn} + \text{CuSO}_4 \rightarrow \text{ZnSO}_4 + \text{Cu} \]

These chemical properties illustrate the reactivity and versatility of metals in various chemical environments. Understanding these properties is crucial for applications in metallurgy, manufacturing, and everyday use of metals in industries ranging from construction to electronics.

Metals and non-metals exhibit contrasting behaviors in chemical reactions due to their distinct properties.

 Reactions of Metals:

1. Reaction with Acids:

   Salt and hydrogen gas are produced when Metals react with acids . For example, when  zinc (Zn) reacts with hydrochloric acid (HCl):

 

   \[ \text{Zn} + 2\text{HCl} \rightarrow \text{ZnCl}_2 + \text{H}_2 \]

 

   Here, zinc displaces hydrogen from hydrochloric acid to form zinc chloride and hydrogen gas.

2. Reaction with Oxygen:

   Metals react with oxygen to form metal oxides. For instance, magnesium (Mg) reacts with oxygen (O₂) to form magnesium oxide (MgO):

 

   \[ 2\text{Mg} + \text{O}_2 \rightarrow 2\text{MgO} \]

   This reaction is typically exothermic and produces a bright white light, often seen in magnesium ribbon burning in air.

3. Reaction with Water:

   Some metals react with water to produce metal hydroxides and hydrogen gas. Sodium (Na), for example, reacts vigorously with water:

   \[ 2\text{Na} + 2\text{H}_2\text{O} \rightarrow 2\text{NaOH} + \text{H}_2 \]

   This reaction is highly exothermic, releasing heat and hydrogen gas.

 

 Reactions of Non-Metals:

 

1. Reaction with Oxygen:

   Non-metals react with oxygen to form oxides. Carbon (C) combines with oxygen (O₂) to form carbon dioxide (CO₂):

 

   \[ \text{C} + \text{O}_2 \rightarrow \text{CO}_2 \]

   This reaction is essential in combustion processes and respiration.

2. Reaction with Hydrogen:

   Non-metals can react with hydrogen to form hydrides. For example, nitrogen (N₂) reacts with hydrogen (H₂) to form ammonia (NH₃):

   \[ \text{N}_2 + 3\text{H}_2 \rightarrow 2\text{NH}_3 \]

 

   Ammonia is a vital compound used in fertilizers and industrial processes.

3. Acid-Base Reactions:

   Non-metals, especially acidic non-metals like sulfur (S), react with bases to form salts. Sulfuric acid (H₂SO₄), for instance, reacts with sodium hydroxide (NaOH):

   \[ \text{H}_2\text{SO}_4 + 2\text{NaOH} \rightarrow \text{Na}_2\text{SO}_4 + 2\text{H}_2\text{O} \]

   This reaction produces sodium sulfate and water.

 

Metals tend to donate electrons to form cations and react with acids and oxygen, while non-metals often gain electrons to form anions and participate in acid-base reactions. These contrasting reactions showcase the diverse chemical behaviors of metals and non-metals, influencing their applications in industries such as metallurgy, agriculture, and manufacturing.

MCQs

Physical Properties of Metals:

 

1. Which property of metals allows them to be hammered into thin sheets?

   - A) Ductility

   - B) Malleability

   - C) Conductivity

   - D) Density

   - Answer: B) Malleability

2. Which metal is known for its exceptional conductivity of electricity?

   - A) Iron

   - B) Lead

   - C) Copper

   - D) Aluminum

   - Answer: C) Copper

 

3. Which physical property of metals makes them shiny and reflective?

   - A) Density

   - B) Malleability

   - C) Opacity

   - D) Luster

   - Answer: D) Luster

 

4. Which metal is commonly used in aircraft due to its lightweight and high strength-to-weight ratio?

   - A) Gold

   - B) Titanium

   - C) Silver

   - D) Nickel

   - Answer: B) Titanium

 

5. Which metal is liquid at room temperature?

   - A) Iron

   - B) Aluminum

   - C) Mercury

   - D) Zinc

   - Answer: C) Mercury

 

Physical Properties of Non-metals:

 

6. Which physical property of non-metals makes them generally poor conductors of electricity?

   - A) Brittleness

   - B) Ductility

   - C) Opacity

   - D) Electrical conductivity

   - Answer: D) Electrical conductivity

 

7. Which non-metal is known for its allotropes including diamond and graphite?

   - A) Carbon

   - B) Oxygen

   - C) Nitrogen

   - D) Sulfur

   - Answer: A) Carbon

 

8. Which non-metal is essential for plant growth and is a component of fertilizers?

   - A) Oxygen

   - B) Hydrogen

   - C) Nitrogen

   - D) Sulfur

   - Answer: C) Nitrogen

 

9. Which non-metal exists as a diatomic gas under normal conditions?

   - A) Chlorine

   - B) Phosphorus

   - C) Sulfur

   - D) Fluorine

   - Answer: A) Chlorine

 

10. Which non-metal is used in matches due to its flammable properties?

    - A) Oxygen

    - B) Phosphorus

    - C) Nitrogen

    - D) Hydrogen

    - Answer: B) Phosphorus

 

Mixed Questions (Metals and Non-metals):

 

11. Which property is common to both metals and non-metals?

    - A) Luster

    - B) Malleability

    - C) Ductility

    - D) Conductivity

    - Answer: A) Luster

 

12. Which metal reacts with water to produce hydrogen gas?

    - A) Sodium

    - B) Aluminum

    - C) Iron

    - D) Copper

    - Answer: A) Sodium

 

13. Which non-metal is commonly found in proteins and nucleic acids?

    - A) Oxygen

    - B) Carbon

    - C) Nitrogen

    - D) Hydrogen

    - Answer: C) Nitrogen

 

14. Which metal is alloyed with tin to create pewter?

    - A) Copper

    - B) Lead

    - C) Zinc

    - D) Aluminum

    - Answer: B) Lead

 

15. Which non-metal is used in the manufacture of fertilizers and explosives?

    - A) Carbon

    - B) Phosphorus

    - C) Sulfur

    - D) Chlorine

    - Answer: B) Phosphorus

 

16. Which property of metals allows them to conduct heat efficiently?

    - A) Opacity

    - B) Malleability

    - C) Brittleness

    - D) Conductivity

    - Answer: D) Conductivity

 

17. Which metal is used as a protective coating for iron to prevent rusting?

    - A) Zinc

    - B) Silver

    - C) Gold

    - D) Nickel

    - Answer: A) Zinc

 

18. Which non-metal is essential for respiration and combustion processes?

    - A) Carbon

    - B) Nitrogen

    - C) Oxygen

    - D) Sulfur

    - Answer: C) Oxygen

 

19. Which metal is commonly used in electrical wiring due to its high conductivity and resistance to corrosion?

    - A) Aluminum

    - B) Nickel

    - C) Copper

    - D) Zinc

    - Answer: C) Copper

 

20. Which non-metal is used in the production of sulfuric acid, one of the most widely used industrial chemicals?

    - A) Carbon

    - B) Nitrogen

    - C) Oxygen

    - D) Sulfur

    - Answer: D) Sulfur

 

Here are (MCQs) with answers on metals and non-metals that are commonly asked in exams like NTSE (National Talent Search Examination):

 

Metals and Non-metals MCQs:

1. Which metal is liquid at room temperature?

   - A) Iron

   - B) Aluminum

   - C) Mercury

   - D) Copper

   - Answer: C) Mercury

 

2. Which non-metal is present in all acids?

   - A) Carbon

   - B) Hydrogen

   - C) Oxygen

   - D) Nitrogen

   - Answer: B) Hydrogen

 

3. Which property of metals allows them to be drawn into wires?

   - A) Malleability

   - B) Conductivity

   - C) Luster

   - D) Opacity

   - Answer: A) Malleability

 

4. Which non-metal is a major constituent of the Earth's atmosphere?

   - A) Carbon

   - B) Nitrogen

   - C) Oxygen

   - D) Sulfur

   - Answer: B) Nitrogen

 

5. Which metal is used for making galvanized iron?

   - A) Zinc

   - B) Copper

   - C) Aluminum

   - D) Lead

   - Answer: A) Zinc

 

6. Which non-metal is used in making gunpowder?

   - A) Carbon

   - B) Sulfur

   - C) Oxygen

   - D) Nitrogen

   - Answer: B) Sulfur

 

7. Which property of non-metals makes them poor conductors of electricity?

   - A) Luster

   - B) Malleability

   - C) Ductility

   - D) Electrical conductivity

   - Answer: D) Electrical conductivity

 

8. Which metal is known for its resistance to corrosion and is used in making aircraft bodies?

   - A) Iron

   - B) Aluminum

   - C) Silver

   - D) Gold

   - Answer: B) Aluminum

 

9. Which non-metal is essential for combustion and respiration processes?

   - A) Carbon

   - B) Nitrogen

   - C) Oxygen

   - D) Hydrogen

   - Answer: C) Oxygen

 

10. Which property of metals allows them to reflect light?

    - A) Malleability

    - B) Luster

    - C) Conductivity

    - D) Density

    - Answer: B) Luster

 

These questions cover various aspects of metals and non-metals, including their properties, uses, and significance in everyday life and industrial applications. They are designed to test fundamental knowledge of these materials as commonly assessed in competitive exams like NTSE.

 

Metals MCQs:

 

1. Which metal is known as the "King of Metals"?

   - A) Gold

   - B) Silver

   - C) Platinum

   - D) Copper

   - Answer: A) Gold

 

2. Which metal is used in galvanization to coat iron to prevent rusting?

   - A) Zinc

   - B) Aluminum

   - C) Nickel

   - D) Tin

   - Answer: A) Zinc

 

3. The metal which  is the best conductor of electricity?

   - A) Copper

   - B) Aluminum

   - C) Silver

   - D) Iron

   - Answer: C) Silver

 

4. The metal which is alloyed with tin to make pewter?

   - A) Lead

   - B) Copper

   - C) Zinc

   - D) Aluminum

   - Answer: A) Lead

 

5. Which metal is essential for the production of stainless steel?

   - A) Chromium

   - B) Nickel

   - C) Titanium

   - D) Cobalt

   - Answer: A) Chromium

 

6. Which metal is used as a catalyst in the hydrogenation of vegetable oils?

   - A) Platinum

   - B) Palladium

   - C) Rhodium

   - D) Iron

   - Answer: B) Palladium

 

7. Which metal is commonly used in electrical wiring due to its high conductivity and affordability?

   - A) Aluminum

   - B) Copper

   - C) Silver

   - D) Gold

   - Answer: B) Copper

 

8. Which metal is used in the manufacture of lead-acid batteries?

   - A) Iron

   - B) Zinc

   - C) Lead

   - D) Nickel

   - Answer: C) Lead

 

9. Which metal is found in its pure state as nuggets or grains in riverbeds and sedimentary deposits?

   - A) Silver

   - B) Gold

   - C) Platinum

   - D) Copper

   - Answer: B) Gold

 

10. Which metal is added to steel to increase its hardness and wear resistance?

    - A) Aluminum

    - B) Manganese

    - C) Tin

    - D) Magnesium

    - Answer: B) Manganese

 

11. Which metal is used in the production of magnets?

    - A) Iron

    - B) Copper

    - C) Zinc

    - D) Nickel

    - Answer: D) Nickel

 

12. Which metal is used in making coinage due to its durability and resistance to corrosion?

    - A) Copper

    - B) Zinc

    - C) Nickel

    - D) Aluminum

    - Answer: A) Copper

 

13. Which metal is commonly used in the aerospace industry due to its lightweight and high strength-to-weight ratio?

    - A) Iron

    - B) Lead

    - C) Titanium

    - D) Platinum

    - Answer: C) Titanium

 

14. Which metal is used in the catalytic converters of automobiles to reduce emissions?

    - A) Palladium

    - B) Silver

    - C) Gold

    - D) Rhodium

    - Answer: D) Rhodium

 

15. Which metal is used in the filament of incandescent light bulbs due to its high melting point?

    - A) Tungsten

    - B) Aluminum

    - C) Silver

    - D) Platinum

    - Answer: A) Tungsten

 

16. Which metal is commonly used in the production of pipes and plumbing fixtures due to its resistance to corrosion?

    - A) Copper

    - B) Zinc

    - C) Aluminum

    - D) Lead

    - Answer: A) Copper

 

17. Which metal is used in the production of nuclear reactors due to its ability to absorb neutrons?

    - A) Uranium

    - B) Thorium

    - C) Plutonium

    - D) Beryllium

    - Answer: A) Uranium

 

18. Which metal is used in the production of mirrors due to its reflective properties?

    - A) Silver

    - B) Aluminum

    - C) Gold

    - D) Chromium

    - Answer: A) Silver

 

19. Which metal is used in the manufacture of stainless steel along with iron and chromium?

    - A) Nickel

    - B) Zinc

    - C) Cobalt

    - D) Molybdenum

    - Answer: A) Nickel

 

20. Which metal is known for its superconducting properties at extremely low temperatures?

    - A) Copper

    - B) Aluminum

    - C) Lead

    - D) Mercury

    - Answer: D) Mercury

 

These questions cover a range of metals, their properties, uses, and significance in various industries, providing a comprehensive review suitable for NTSE exam preparation.