Learn
Games

11.4.1 - Activity 11.1

Interactive Audio Lesson

Listen to a student-teacher conversation explaining the topic in a relatable way.

Basic Concepts of Conductors

Unlock Audio Lesson

Signup and Enroll to the course for listening the Audio Lesson

Teacher
Teacher

Today we're diving into the world of conductors! Who can tell me what a conductor is?

Student 1
Student 1

Isn't it something that conducts electricity, like metal?

Teacher
Teacher

Exactly! Metals like copper and aluminum are good conductors. On the other hand, materials like rubber and plastic do not conduct electricity. We call them poor conductors.

Student 2
Student 2

So, if I have a rubber glove and I touch something electrical, it's safer?

Teacher
Teacher

Right! That's why we avoid touching electrical appliances with wet hands—water can conduct electricity, making it dangerous. Remember, 'stay dry, stay safe'! Now, what happens with liquids? Do they conduct electricity like solids?

Testing Liquids

Unlock Audio Lesson

Signup and Enroll to the course for listening the Audio Lesson

Teacher
Teacher

Let's conduct a test to see if liquids conduct electricity! What liquid should we try first?

Student 3
Student 3

How about lemon juice? My mom uses it for cooking!

Teacher
Teacher

Great choice! Lemon juice is acidic, which generally makes it a good conductor. We will use a tester to check this. What do we expect to happen?

Student 4
Student 4

If it conducts, the bulb will glow!

Teacher
Teacher

Correct! Let's prepare the tester and see what happens. Remember, the tester completes a circuit, and when the current flows, the bulb glows. If it doesn’t glow, the liquid may be a poor conductor.

Chemical Reactions from Electric Current

Unlock Audio Lesson

Signup and Enroll to the course for listening the Audio Lesson

Teacher
Teacher

After testing several liquids, what did we observe? Do we notice any gas bubbles or color changes?

Student 1
Student 1

Yes! When we used lemon juice, the bulb glowed and there were bubbles!

Teacher
Teacher

Exactly! This demonstrates a chemical reaction happening due to the electric current. Can anyone tell me why the bulbs glow or why we see bubbles?

Student 2
Student 2

It’s because the electric current heats the filament in the bulb!

Teacher
Teacher

Good job! When the current flows, it not only lights the bulb but can also cause changes in the solution, indicating that chemical reactions are taking place. This leads us to important applications of electrical current in everyday scenarios!

Applying Knowledge on Conductors

Unlock Audio Lesson

Signup and Enroll to the course for listening the Audio Lesson

Teacher
Teacher

Now that we understand what makes a good or poor conductor, let’s think about everyday items. What common liquids or materials might we test at home?

Student 3
Student 3

We could try vinegar, tap water, or even soda!

Teacher
Teacher

Excellent suggestions! Each of these will have different conductivity levels. Why do we think some liquids like distilled water might not conduct?

Student 4
Student 4

Because it doesn't have minerals or salts in it?

Teacher
Teacher

Exactly! Distilled water is a poor conductor. But when we add salt, it becomes a good conductor. Remember, substances dissolved in water often create conductive solutions!

Reviewing Key Concepts

Unlock Audio Lesson

Signup and Enroll to the course for listening the Audio Lesson

Teacher
Teacher

To wrap up, why is understanding conductors and the chemical effects of electric current important?

Student 1
Student 1

It helps us know what is safe and what can conduct electricity!

Student 2
Student 2

And it shows us the chemical changes that can happen with electric current!

Teacher
Teacher

Exactly! Recognizing which substances conduct electricity can help keep us safe and show us remarkable chemical reactions. Always remember: conductors are key to understanding electricity in our lives!

Introduction & Overview

Read a summary of the section's main ideas. Choose from Basic, Medium, or Detailed.

Quick Overview

This section explores the chemical effects of electric current on various liquids, utilizing testers to observe electrical conductivity.

Standard

In this section, students engage in experiments using testers to determine the conductivity of liquids, exploring the concepts of good and poor conductors while understanding the chemical reactions that occur when electric current flows through a conducting solution.

Detailed

Youtube Videos

Chemical Effects of Electric Current Class 8 Science - Electroplating
Chemical Effects of Electric Current Class 8 Science - Electroplating
CHEMICAL EFFECTS OF ELECTRIC CURRENT
CHEMICAL EFFECTS OF ELECTRIC CURRENT
Chemical Effects of Electric current Activity 8
Chemical Effects of Electric current Activity 8
Chemical Effects of Electric Current | Full Chapter Revision under 30 mins | Class 8 Science
Chemical Effects of Electric Current | Full Chapter Revision under 30 mins | Class 8 Science
Class 8 Science Chapter 14 Chemical Effects of Electric Current - Do Liquids Conduct Electricity?
Class 8 Science Chapter 14 Chemical Effects of Electric Current - Do Liquids Conduct Electricity?
Chemical Effects of Electric Current | NCERT Activities Explained and Quiz | Class 8 | BYJU'S
Chemical Effects of Electric Current | NCERT Activities Explained and Quiz | Class 8 | BYJU'S
Classroom experiments-Electroplating | Class 8 Chemical effects of electricity
Classroom experiments-Electroplating | Class 8 Chemical effects of electricity
Class 8 - Activity to demonstrate change in colour due to Chemical effect of electric current
Class 8 - Activity to demonstrate change in colour due to Chemical effect of electric current
Change in Colour Caused by Chemical Effect of Electric Current| Class 8 science NCERT activity 1.14
Change in Colour Caused by Chemical Effect of Electric Current| Class 8 science NCERT activity 1.14
Science activity ch 11 Chemical effects of electric current class 8
Science activity ch 11 Chemical effects of electric current class 8

Audio Book

Dive deep into the subject with an immersive audiobook experience.

Testing with a Tester

Unlock Audio Book

Signup and Enroll to the course for listening the Audio Book

Join the free ends of the tester together for a moment. This completes the circuit of the tester and the bulb should glow. However, if the bulb does not glow, it means that the tester is not working. Can you think of the possible reasons? Is it possible that the connections are loose? Or, the bulb is fused? Or, your cells are used up? Check that all the connections are tight. If they are, then replace the bulb with another bulb. Now test if the tester is working or not.

Detailed Explanation

In this step, we are checking if our tester is functioning properly. By joining the free ends together, we create a complete circuit that allows electric current to flow. If the bulb lights up, it indicates that the circuit is working correctly. If the bulb does not light up, it could be due to loose connections, a burnt-out bulb, or depleted batteries. It’s important to troubleshoot to find the issue, which can include tightening any loose connections or replacing faulty components.

Examples & Analogies

Think of it like checking if a flashlight is working. If you turn on the flashlight and it doesn’t light up, you might check the batteries (like checking the cells in our tester), the bulb (similar to the tester’s bulb), or if the cap is tightly closed (like our connections).

Using the Tester for Liquids

Unlock Audio Book

Signup and Enroll to the course for listening the Audio Book

Now that our tester is working, let us use it to test the various liquids. (Caution: While checking your tester, do not join its free ends for more than a few seconds. Otherwise, the cells of the battery will drain very quickly.)

Detailed Explanation

Now that we ensured the tester works, we will use it to test different liquids to see if they conduct electricity. It is vital to remember to connect the ends only briefly, as prolonged contact can deplete the battery quickly. When we dip the tester into the liquids, we are checking whether the liquids allow electric current to flow through them.

Examples & Analogies

Imagine testing your drinks at a party. If you test water, juice, and soda to see which one is fizzy or sweet, you're essentially testing different liquids. In our case, we want to find out which liquids can conduct electricity, similar to discovering which drinks give a strong taste or fizz.

Classifying Liquid Conductors

Unlock Audio Book

Signup and Enroll to the course for listening the Audio Book

When the liquid between the two ends of the tester allows the electric current to pass, the circuit of the tester becomes complete. The current flows in the circuit and the bulb glows. When the liquid does not allow the electric current to pass, the circuit of the tester is not complete and the bulb does not glow.

Detailed Explanation

This chunk explains how we determine if a liquid is a good or poor conductor of electricity. If the bulb lights up when dipped in a liquid, it indicates that the liquid allows current to pass and is therefore a good conductor. If the bulb stays off, it means the liquid does not conduct electricity, classifying it as a poor conductor. This binary outcome helps us understand the conductive properties of different liquids.

Examples & Analogies

Think about lights in a house; when you flip a switch and the light turns on, electricity is flowing through the wires. If you flip the switch and nothing happens, it means there's a problem—similar to our tester indicating poor conductivity when the bulb doesn’t glow.

Understanding Weak Currents

Unlock Audio Book

Signup and Enroll to the course for listening the Audio Book

In some situations even though the liquid is conducting, the bulb may not glow. It may have happened in Activity 11.2. What can be the reason? Do you remember why the bulb glows when the electric current passes through it? Due to the heating effect of current, the filament of the bulb gets heated to a high temperature and it starts glowing. However, if the current through a circuit is too weak, the filament does not get heated sufficiently and it does not glow. And why is the current in the circuit weak?

Detailed Explanation

Here, we learn that sometimes a liquid may conduct electricity, but if the electric current is too weak, the tester's bulb will not illuminate. This occurs due to insufficient energy being supplied to heat the filament of the bulb. Just because a liquid conducts does not mean it conducts well enough to create a strong current. It’s a reminder to differentiate between mere conductivity and the strength of that conductivity.

Examples & Analogies

Consider water flowing through a garden hose. If you barely turn on the tap, the flow is weak, and not enough water will reach the end of the hose. However, if you turn the tap fully open, a strong stream of water flows. In our tester analogy, we are observing how strong or weak the liquid's conductivity affects the light bulb's glow.

Definitions & Key Concepts

Learn essential terms and foundational ideas that form the basis of the topic.

Key Concepts

  • Good Conductors: Materials like metals that allow easy current flow.

  • Poor Conductors: Materials such as rubber and plastic that restrict current.

  • Testing Conductivity: Using tools like testers to observe if liquids conduct electricity.

  • Chemical Reactions: Transformations occurring when electric current flows through a conducting solution.

  • Electrolysis: The process which includes the movement of ions in a conducting solution.

  • Applications: Practical uses of understanding electrical conductivity in real life.

Examples & Real-Life Applications

See how the concepts apply in real-world scenarios to understand their practical implications.

Examples

  • Testing lemon juice with a homemade tester to check for conductivity.

  • Dissolving salt in distilled water to see an increase in conductivity.

Memory Aids

Use mnemonics, acronyms, or visual cues to help remember key information more easily.

🎵 Rhymes Time

  • Liquids that conduct can make bulbs glow bright, but with distilled water, nothing's in sight.

📖 Fascinating Stories

  • Imagine a party of liquids where lemon juice brought the most energy! The electric current made the room light up while distilled water sat quietly, unable to shine.

🧠 Other Memory Gems

  • Conductors Can Go: Copper, Aqueous Solutions, but Distilled Water says No!

🎯 Super Acronyms

GEL

  • Good Electrolytes are Liquids like salty or acidic ones.

Flash Cards

Review key concepts with flashcards.

Glossary of Terms

Review the Definitions for terms.

  • Term: Conductor

    Definition:

    A material that allows electric current to pass through it easily.

  • Term: Poor Conductor

    Definition:

    A material that does not allow electric current to pass through easily.

  • Term: Chemical Reaction

    Definition:

    A process that leads to the transformation of one set of chemical substances to another.

  • Term: Electrolyte

    Definition:

    A substance that produces an electrically conducting solution when dissolved in a polar solvent.

  • Term: Electrolysis

    Definition:

    The process of using electric current to drive a reaction that would not occur spontaneously.