LECTURE -3 : CLASS VIII : SCIENCE : CHAPTER 4 : DISPLACEMENT REACTIONS AND USES OF METALS AND NON-METALS

 CLASS VIII   |    SCIENCE    |    CHAPTER 4: 

METALS AND NON-METALS

      Notes prepared by Subhankar Karmakar

___________________________________________________________________________________

• A more reactive metal displaces a less reactive metal from its salt solution. 
• When a more reactive metal is placed in a salt solution of a less reactive metal, then the more reactive metal metal displaces the less reactive metal from its salt solution.
• A displacement reaction, also known as a replacement reaction, is a type of chemical reaction in which one element replaces another in a compound.
• This type of reaction occurs when a more reactive element replaces a less reactive element in a compound.
• The displaced element is released as a free element, and the newly formed compound contains the element that did the displacing.
• Displacement reactions are often used to extract metals from their ores, and they are also important in organic chemistry reactions.
• One common example of a displacement reaction is the reaction of iron with copper sulfate to form iron sulfate and copper.

Example, Reaction of Iron Metal with Copper Sulphate solution: 

Copper Sulphate + Iron → Iron Sulphate + Copper 

CuSO₄ + Fe → FeSO₄ + Cu

METALS	NON-METALS
1.      1.    Metals form basic oxides.	1.    Non-metals form acidic oxides
2.       2.  Most metals react with water (or steam) to produce Hydrogen gas.	2.    Non-metals do not react with water.
3.      3.  Metals react with dilute acids to produce Hydrogen gas.	3.    Non metals do not react with dilute acids.

USES OF METALS:

Some of the most uses of metals are given below : 

1: Iron, copper, and Aluminium metals are used to make cooking utensils and water boilers for factories.

2: Copper metal is used for making electric wires for household wiring, electric motors, armature of dynamos, and many other electrical appliances. Aluminium metal is used for making electric cables and over-head electric transmission lines. 

3. Aluminium foils are used for packaging medicines, chocolates, food items, and many other materials. 

4. Aluminium metal in the form of alloys is used to make aeroplanes. 

USES OF NON-METALS:

Non-metals have many important uses in our daily lives. Here are some examples:

1. Oxygen (O) is a non-metal that is essential for life. It makes up about 21% of the air we breathe and is used by living organisms to produce energy through respiration.
2. Nitrogen (N) is another non-metal that makes up about 78% of the air we breathe. It is used in the production of fertilizers and as a coolant in certain industrial processes.
3. Carbon (C) is a non-metal that is found in all living organisms. It is used in the production of fuels, such as coal and oil, and is also used in the manufacturing of various products, including plastics, rubber, and textiles.
4. Chlorine (Cl) is a non-metal that is used as a disinfectant in swimming pools and water treatment plants. It is also used in the production of various chemicals, including PVC plastics.
5. Hydrogen (H) is a non-metal that is used as a fuel in vehicles and as a source of energy in fuel cells. It is also used in the production of ammonia, which is used in the production of fertilizers.
6. Sulfur (S) is a non-metal that is used in the production of sulfuric acid, which is a key component in the production of many chemicals and fertilizers. It is also used in the production of rubber and as a fungicide in agriculture.

QUESTIONS ON MOTION IN ONE DIMENSION

Questions on motion in one dimension so that objective of knowledge construction is achieved

1. What is the definition of motion in one dimension, and how does it differ from motion in multiple dimensions?

2. What are some common examples of motion in one dimension, and how can they be described using mathematical equations?

3. How does the concept of velocity relate to motion in one dimension, and how can it be calculated using distance and time measurements?

4. How does acceleration affect motion in one dimension, and what are some common examples of situations where acceleration is present?

5. How does the principle of inertia apply to motion in one dimension, and how can it be used to explain the behavior of objects in motion?

6. What is the difference between uniform and non-uniform motion in one dimension, and how can this be observed in real-world situations?

7. How do external forces, such as friction or air resistance, affect motion in one dimension, and how can they be accounted for in mathematical models?

8. What are some common misconceptions or misunderstandings about motion in one dimension, and how can they be addressed to promote a more accurate understanding of this concept?

9. How can motion in one dimension be applied to real-world scenarios, such as the motion of vehicles or the trajectory of a projectile?

10. What are some current research topics related to motion in one dimension, and how do they contribute to our understanding of this concept?

Questions on motion in one dimension that are designed to facilitate knowledge construction through case-based reasoning:

1. A car is moving in a straight line with a constant velocity of 20 m/s. How far will it travel in 5 seconds?

2. A ball is thrown upward with an initial velocity of 30 m/s. How long will it take to reach its maximum height? What is the maximum height that it will reach?

3. A train is traveling with a constant acceleration of 2 m/s^2. If it starts from rest, how long will it take to reach a velocity of 60 m/s? How far will it travel during that time?

4. A roller coaster starts at the top of a hill with an initial velocity of 0 m/s. It then travels down the hill with a constant acceleration of 5 m/s^2. How fast will it be traveling after 10 seconds? How far will it have traveled during that time?

5. A person is walking at a constant speed of 1.5 m/s. How long will it take for them to travel a distance of 500 meters?

6. A student throws a ball vertically upwards with an initial velocity of 20 m/s. How high does the ball go and how long does it take to reach its maximum height? What is the ball's velocity and acceleration at its maximum height?

7. A car is driving down a straight road at a constant speed of 60 km/hr. Suddenly, the driver applies the brakes and the car comes to a stop in 5 seconds. What is the car's acceleration during this time? How far does the car travel before coming to a stop?

8. A cyclist is riding down a hill with an initial velocity of 10 m/s. The cyclist then applies the brakes and comes to a stop after traveling 100 meters. What is the cyclist's acceleration during this time? How long does it take for the cyclist to come to a stop?

9. A ball is thrown off a building with an initial velocity of 30 m/s. If the building is 50 meters tall, how long does it take for the ball to hit the ground? What is the ball's velocity just before it hits the ground?

10. A rocket is launched vertically upwards from the ground with an initial velocity of 500 m/s. If the rocket's engine shuts off after 10 seconds, how high does the rocket go? What is the rocket's velocity and acceleration at its maximum height? How long does it take for the rocket to fall back to the ground?

For each of these questions, students can use the given information to construct a mental model of the situation, and then apply the relevant physics principles to arrive at a solution. By working through these case-based problems, students will develop a deeper understanding of the concepts of motion in one dimension, and will be better equipped to apply those concepts to new situations in the future.

THE FUNCTIONS OF KIDNEY IN HUMAN BEINGS

THE STRUCTURE OF A KIDNEY

• Each kidney is made up of a large number of excretory units called nephrons. 

• Each nephron has a cup shaped bag at its upper end which is called Bowman's capsule. 

• The lower end of Bowman's capsule is tube shaped and it is called a tubule. 

• The Bowman's capsule and the tubule taken together make a nephron. 

• One end of the tubule is connected to the Bowman's capsule and the other end is connected to a urine-collecting duct of the kidney. 

• The Bowman's capsule contains a bundle of blood capillaries which is called glomerulus.

• One end of the glomerulus is attached to the renal artery which brings the dirty blood containing the urea waste into it.   

THE FUNCTIONS OF KIDNEY IN HUMAN BEINGS

The kidneys are a pair of bean-shaped organs located in the abdominal cavity, and they play several crucial roles in maintaining the overall health and wellbeing of human beings. Some of the primary functions of the kidneys include:

Regulating fluid balance: The kidneys regulate the balance of fluids in the body by filtering excess fluids and removing them as urine.

Removing waste products: The kidneys filter waste products, such as urea, uric acid, and creatinine, from the blood and eliminate them through urine.

Maintaining electrolyte balance: The kidneys help maintain the balance of electrolytes, such as sodium, potassium, and calcium, in the body.

Regulating blood pressure: The kidneys play a role in regulating blood pressure by controlling the amount of fluid in the bloodstream.

Producing hormones: The kidneys produce hormones, such as erythropoietin and renin, that help regulate the production of red blood cells and control blood pressure, respectively.

Activating vitamin D: The kidneys play a role in activating vitamin D, which is essential for maintaining strong bones.

Overall, the kidneys are essential organs that play multiple vital roles in maintaining the overall health and homeostasis of the body. Dysfunction or failure of the kidneys can result in severe health consequences, such as fluid imbalances, electrolyte disturbances, and accumulation of waste products in the bloodstream.

Draw a well labelled diagram of L.S. of the human kidney

Experential Learning

The theory of experiential learning, also known as the Kolb cycle or Kolb's learning styles, was developed by David A. Kolb in the 1970s. This theory suggests that learning occurs through a four-stage cycle of concrete experience, reflective observation, abstract conceptualization, and active experimentation. This cycle can be applied to any type of learning, whether it is formal education or everyday life experiences.

1. The first stage of the cycle is concrete experience, where the learner engages in a real-world experience. This could be anything from participating in a science experiment to attending a business meeting. In this stage, the learner is actively involved in the experience and is gaining knowledge through their senses.
2. The second stage is reflective observation, where the learner reflects on the experience and considers what happened. This involves observing and reviewing the experience from different perspectives and examining the emotions and feelings that were experienced during the event. This stage is critical to the learning process as it allows the learner to assess what happened and to gain insight into how they can improve in the future.
3. The third stage is abstract conceptualization, where the learner draws conclusions from the experience and formulates new ideas and concepts. This involves thinking critically about the experience and using existing knowledge and ideas to make sense of what happened. In this stage, the learner is able to connect the experience to theoretical concepts and principles, and to develop new insights and theories.
4. The fourth and final stage is active experimentation, where the learner applies their new knowledge and ideas to real-world situations. This involves testing new ideas, experimenting with new approaches, and trying out new ways of doing things. In this stage, the learner is able to put their ideas into practice and to see how they work in the real world.

According to Kolb's theory, everyone has a preferred learning style that is based on their personality and individual preferences. There are four different learning styles: diverging, assimilating, converging, and accommodating.

1. Diverging learners prefer to learn through concrete experiences and reflective observation. They tend to be imaginative and emotional, and they enjoy exploring new ideas and concepts.
2. Assimilating learners prefer to learn through abstract conceptualization and reflective observation. They tend to be logical and analytical, and they enjoy exploring ideas and theories.
3. Converging learners prefer to learn through abstract conceptualization and active experimentation. They tend to be practical and goal-oriented, and they enjoy applying new ideas and theories to real-world situations.
4. Accommodating learners prefer to learn through concrete experience and active experimentation. They tend to be hands-on and intuitive, and they enjoy experimenting with new ideas and approaches.

The theory of experiential learning has many applications in education and training. It emphasizes the importance of hands-on experiences and encourages learners to take an active role in their own learning. This approach can be particularly effective for adult learners, who often learn best through practical experiences and real-world applications.

Experiential learning can also be used to enhance professional development and team building. By engaging in experiential activities, individuals can develop new skills, improve their communication and problem-solving abilities, and gain new insights into their own strengths and weaknesses. Teams can also benefit from experiential learning activities, as they provide opportunities for members to work together, build trust, and develop a shared sense of purpose and identity.

Experiential Learning cycles

Experiential learning cycles are models that describe the process of learning through experience. One of the most popular models is the Kolb experiential learning cycle, which consists of four stages:

1. Concrete Experience: The first stage involves experiencing a new situation or event that challenges an individual's existing knowledge or understanding.
2. Reflective Observation: The second stage involves reflecting on the experience and analyzing what happened, what worked, and what didn't work. This stage involves asking questions and examining the experience from different perspectives.
3. Abstract Conceptualization: The third stage involves forming abstract concepts and generalizations based on the experience and reflection. This stage involves synthesizing information and making connections between the experience and existing knowledge.
4. Active Experimentation: The fourth stage involves applying what was learned to a new situation or problem. This stage involves testing hypotheses, experimenting with new approaches, and taking action based on what was learned.

By cycling through these four stages, an individual can deepen their understanding of a particular topic or problem and improve their ability to apply what they have learned in new situations. Experiential learning cycles are often used in educational settings, but they can also be applied in a variety of contexts, such as in the workplace or in personal development.

HOLI GREETINGS: 2023

Holi Greetings

Holi, also known as the "Festival of Colors", is one of the most vibrant and fun-filled festivals celebrated in India and around the world. The festival marks the victory of good over evil and the arrival of spring, and it is celebrated with great enthusiasm and joy.

As we celebrate Holi this year, let us take a moment to reflect on the true meaning of this festival. It is not just about smearing colors on each other's faces or dancing to the beats of dhol, but it is also about spreading love, happiness, and unity among people from all walks of life.

On this joyous occasion, I would like to extend my warmest greetings and best wishes to all of you. May your life be filled with vibrant colors, sweet melodies, and joyous celebrations.

May this Holi bring you and your loved ones closer together and strengthen the bonds of love and friendship. May the colors of Holi brighten up your life and fill your heart with happiness and positivity.

Let us forget all our differences and come together to celebrate this festival with love and harmony. Let us spread love and joy by sharing sweets, playing with colors, and dancing to the rhythm of Holi songs.

Let us take a moment to remember those who are less fortunate and spread the joy of Holi to them as well. Let us share our happiness and blessings with those in need and make this festival truly memorable for them as well.

This Holi, let us also pledge to protect our environment and celebrate the festival in an eco-friendly manner. Let us use natural colors and avoid wasting water or polluting the environment in any way.

On this special day, let us express our gratitude to the people who have made a difference in our lives and helped us become who we are today. Let us thank our parents, siblings, friends, and all the people who have been there for us through thick and thin.

In conclusion, I would like to wish you all a very happy and colorful Holi. May your life be filled with love, laughter, and joy. May you always find the strength to overcome all obstacles and emerge victorious in all your endeavors. Happy Holi!

QUALITY MANAGEMENT AND IT'S STAGES:

QUALITY MANAGEMENT: 

Quality management is the process of ensuring that a product or service meets the desired level of quality, as defined by the customer or user. It involves a series of stages that help ensure that the quality of the product or service is maintained throughout its lifecycle. These stages are:

Quality Planning: This stage involves identifying the customer's quality requirements and translating them into specific quality objectives for the product or service. This stage also involves determining the resources, processes, and tools required to meet the quality objectives.

Quality Control: This stage involves monitoring and controlling the processes used to create the product or service to ensure that the quality objectives are met. This stage involves the use of statistical quality control techniques, such as statistical process control, to identify and correct quality problems.

Quality Assurance: This stage involves the development and implementation of a quality management system that ensures that the product or service meets the desired level of quality. This stage involves creating policies, procedures, and guidelines that ensure that quality objectives are met consistently.

Quality Improvement: This stage involves continuously improving the quality of the product or service by identifying and addressing quality problems. This stage involves the use of tools such as root cause analysis, process improvement, and Six Sigma to identify and address quality problems.

Overall, quality management is an ongoing process that requires continuous monitoring and improvement to ensure that the product or service meets the desired level of quality.

QUALITY PLANNING:

Quality planning is the first stage in quality management. It involves identifying the quality requirements of the customer or user and translating them into specific quality objectives for the product or service. Quality planning is a critical stage in the quality management process as it lays the foundation for the rest of the quality management stages.

During quality planning, the following activities are typically undertaken:

1. Defining quality objectives: This involves defining the quality requirements that the product or service should meet. Quality objectives should be specific, measurable, achievable, relevant, and time-bound.
2. Identifying quality standards: This involves identifying the quality standards that the product or service should meet, such as ISO standards, industry-specific standards, or customer-specific standards.
3. Establishing quality targets: This involves establishing specific quality targets for the product or service, such as defect rates, cycle times, or customer satisfaction levels.
4. Determining quality assurance and quality control activities: This involves determining the activities that will be used to ensure that the product or service meets the quality objectives, such as inspections, testing, audits, and reviews.
5. Identifying resources: This involves identifying the resources, including personnel, equipment, and materials, needed to achieve the quality objectives.
6. Developing a quality management plan: This involves documenting the quality objectives, standards, targets, activities, and resources in a quality management plan. The quality management plan serves as a roadmap for the rest of the quality management process.

Overall, quality planning is a critical stage in quality management as it helps ensure that the product or service meets the desired level of quality.

QUALITY CONTROL:

Quality control is the second stage in quality management. It involves monitoring and controlling the processes used to create the product or service to ensure that the quality objectives are met. Quality control is an essential stage in the quality management process as it helps identify and correct quality problems before they reach the customer or user.

During quality control, the following activities are typically undertaken:

1. Inspection and testing: This involves inspecting and testing the product or service to ensure that it meets the quality objectives. Inspection and testing may be conducted at various stages of the production process, such as during raw material inspection, in-process inspection, and final inspection.
2. Statistical process control (SPC): This involves using statistical techniques to monitor and control the production process. SPC helps identify trends and patterns in the production process that may indicate quality problems.
3. Corrective action: This involves taking corrective action to address quality problems when they are identified. Corrective action may involve reworking the product, replacing defective parts, or modifying the production process.
4. Documentation: This involves documenting the results of inspections, tests, and corrective actions taken. Documentation is essential for tracking quality performance and identifying opportunities for improvement.

Overall, quality control is a critical stage in quality management as it helps ensure that the product or service meets the desired level of quality. Quality control is a proactive process that helps prevent quality problems from reaching the customer or user.

QUALITY ASSURANCE: 

Quality assurance is the third stage in quality management. It involves the development and implementation of a quality management system that ensures that the product or service meets the desired level of quality. Quality assurance is an essential stage in the quality management process as it provides a framework for maintaining and improving quality over time.

During quality assurance, the following activities are typically undertaken:

1. Quality system development: This involves developing a quality management system that defines the policies, procedures, and guidelines for ensuring that the product or service meets the quality objectives.
2. Quality audits: This involves conducting audits of the quality management system to ensure that it is effective and efficient. Audits may be conducted by internal or external auditors.
3. Training: This involves providing training to employees on the quality management system, quality objectives, and quality standards. Training helps ensure that employees understand their roles and responsibilities in maintaining quality.
4. Management review: This involves regular management reviews of the quality management system to ensure that it is meeting the quality objectives and to identify opportunities for improvement.
5. Continual improvement: This involves identifying opportunities for improvement and making changes to the quality management system to improve quality over time.

Overall, quality assurance is a critical stage in quality management as it helps ensure that the product or service meets the desired level of quality over time. Quality assurance is a proactive process that helps maintain and improve quality by providing a framework for continuous improvement.

QUALITY IMPROVEMENT: 

Quality improvement is the fourth and final stage in quality management. It involves continuously improving the quality of the product or service by identifying and addressing quality problems. Quality improvement is an essential stage in the quality management process as it helps ensure that the product or service remains competitive and meets the changing needs of the customer or user.

During quality improvement, the following activities are typically undertaken:

1. Root cause analysis: This involves identifying the underlying causes of quality problems. Root cause analysis may involve using tools such as fishbone diagrams, Pareto charts, and fault tree analysis.
2. Process improvement: This involves making changes to the production process to address quality problems and improve efficiency. Process improvement may involve using tools such as Lean Six Sigma, Total Quality Management (TQM), and Kaizen.
3. Continual monitoring: This involves monitoring the production process and product or service quality to identify quality problems and opportunities for improvement. Continual monitoring may involve using statistical process control (SPC) and other quality control tools.
4. Customer feedback: This involves obtaining feedback from customers on the quality of the product or service. Customer feedback may be obtained through surveys, focus groups, and other methods.

Overall, quality improvement is a critical stage in quality management as it helps ensure that the product or service remains competitive and meets the changing needs of the customer or user. Quality improvement is a proactive process that helps maintain and improve quality by identifying and addressing quality problems and making changes to the production process.

Accessibility in inclusive classroom

An inclusive classroom is a learning environment that accommodates the diverse learning needs of all students, including those with disabilities, and creates an environment that encourages and values diversity. Accessibility is a critical aspect of an inclusive classroom, and it involves ensuring that all students can access and participate in the learning activities provided.

Here are some ways to promote accessibility in an inclusive classroom:

Physical Accessibility: Ensure that the classroom and learning materials are physically accessible to all students. For example, this might involve ensuring that the classroom is wheelchair accessible, providing ramps, ensuring that there are no tripping hazards, and providing seating arrangements that allow for easy movement.

Technological Accessibility: Provide assistive technology to support students with disabilities, such as text-to-speech software or closed captioning. Ensure that any learning materials, such as online resources, are accessible to all students.

Sensory Accessibility: Consider the sensory needs of students with disabilities, such as those who are deaf or hard of hearing or have visual impairments. Ensure that any learning materials, such as videos or presentations, are accessible to all students, and provide alternative formats as necessary.

Instructional Accessibility: Adapt instructional methods to suit the diverse learning needs of all students. For example, use multiple modes of instruction, such as visual aids, hands-on activities, and verbal instructions, to accommodate different learning styles.

Communication Accessibility: Ensure that communication is accessible to all students. For example, provide interpreters or sign language services for students who are deaf or hard of hearing, and use clear, simple language to support students with learning disabilities.

Emotional Accessibility: Create a supportive and welcoming classroom environment that values and respects all students. Encourage students to share their experiences and perspectives and promote a culture of acceptance and understanding.

Overall, promoting accessibility in an inclusive classroom involves being mindful of the diverse learning needs of all students and taking proactive steps to ensure that all students can participate fully and meaningfully in the learning experience.