Second Week of Teaching Practice

Hi all,

       This blog will be about my second week of Teaching Practice. Each day goes through experiences that teach me new things. The past week students were co-operative, concentrated in class to their best.

Topics Covered this week:

• Kinetic Energy, 
• Potential Energy, 
• True Solution, Colloid and Suspension, 
• Size of molecules in solution,
• Super Saturated Solution, 
• Factors affecting Solution, 
• Classification of mixtures.

Kinetic Energy

Classes began with discussion on the previous topic, "Energy".

• The above-shown activity was demonstrated to the students for them to understand the concept of Kinetic Energy.
• The picture was shown and asked, "What happened to the ball when the moving car hit it?" and "How did the car get the energy to move the ball forward?"
• Students were explained that "the energy possessed by a body by virtue of its motion is kinetic energy". 
• Students were explained that Kinetic energy and momentum are interrelated by the below-shown example.
  
• Students were asked what happens if a powder tin was allowed to slide down over a polished inclined plane and hit the toy car. After doing so the displacement of the car is measured. The experiment is repeated by increasing the height of the inclined plane and filling the tin with sand. 
• When a body of mass m moves with a velocity v, its kinetic energy will be K=1/2 mv²
  .
• The above-shown concept was attained through the inquiry training model.

Potential Energy
  Topic began with the introduction of a situation in which, a boy names salin was returning from school on his bicycle, in which he had a bag containing 10 kg of rice along with his school bag full of books. And when he reached an ascent on the road he was tired.

• Discussion was done on
• Why Salin couldn't pedal his bicycle up the incline?
• And whether students have gone through these situations?

• Activity began with the following  questions, 
• Isn't work to be done to lift the bodies?", 
• "Against which force did work done here?", by showing the below picture and question.

• The concept of Position and Potential Energy is explained. The Potential energy of a body at a specific height depends on the position at which the potential is considered zero. The ground is considered as the position for zero potential, unless and otherwise other methods are mentioned.

• The above picture is shown to students are asked: " At which height from the floor is maximum work done on the body?"
• The energy possessed by a body by virtue of its position is the potential energy

                                    i.e., potential energy U = mgh

Activity: Students were asked to identify more situations in which potential energy is acquired by virtue of position and write them down. Students understood that when height varies, the potential energy also varies. 

• The concept of potential energy due to strain is also explained by showing the below picture as an example.

• Students were explained that the work we have done on the spring to change its shape would remain in it as its energy and that this energy is called potential energy due to strain.
• Students themselves gave 'A stretched bow' and 'a rubber band in stretched position' as an example of situations where one form of energy is transformed into other forms.

True Solutions Colloid and Suspensions 
Size of molecules in solution

• Class began by asking questions of their past knowledge about Solutions, Colloid and Suspensions by giving examples like sugar solution, milk and muddy water and asking the students to differentiate them. 
• Experiment was done by the students
• Students were asked to take equal amounts of water in three separate beakers. Copper Sulphate crystals in first, milk in the second and Chalk powder in the third beaker were added. The solutions were stirred and left undisturbed for some time. 
• Observation done by students for the settling of substances at the bottom.
• Students stirred it again and a beam of light through the sides of the three beakers. Observations were ticked in the below-shown table.

• Students were able to differentiate the true solution(Beaker 1), Colloid(Beaker 2), suspension (Beaker 3). 
• Students tabulated the characteristics of each mixture in the below table from their observation

• From the observations made students concluded that the difference observed is due to the change in size of the particles present in them.
• Following questions were asked 
• Which mixture in these beakers has the smallest particle size?
• How was this identified?
• Which mixture has the biggest particle size?
• Explanation and Conclusion: 
• The size of solute particles present in a solution is so small that it cannot be seen with the naked eye. Since these particles are very minute, they cannot scatter a beam of light. Hence, the path of the light is not visible.
• In the case of the colloids, the solute (colloidal) particle size is comparatively bigger. Hence, they scatter a beam of light, thus making the path of the beam visible.
• Particles of suspensions are big enough to be seen with the naked eye. The light falling on them is reflected almost completely. They gradually settle down under the influence of gravity. 
• Students were asked to evaluate the following mixtures as a follow up activity:

Ink, muddy water, milk, sugar solution, dilute rice water.

• Students classified them into true solutions, colloids, and suspensions below shown column.

• Students were asked whether they have noticed the path of light beam can be clearly seen due to the dust particles in a cinema theater and in smart classrooms where visuals are shown using a projector? And were asked the reason behind this.

Supersaturated Solutions
Students were asked about adding sugar to the hot tea and cold water and asks in what situation does the sugar dissolve quickly and arrived at the concept of Supersaturated solutions.

• A student was given a beaker containing water add salt and heat the water and observe the changes.
• Question posed: Is there any change in the amount of solute dissolved when the temperature changes?
• The experiment is repeated with the saturated solution of ammonium chloride.
• Students understood that, a solution, which contains more amount of solute than that is required to saturate it, is known as a supersaturated solution.

Factors affecting Solution

• Discussion was done about the solubility of different substances like sugar, salt and potassium permanganate in water and arrived at the concept of Factors affecting Solution.
• Questions were asked on different solubility and different temperatures for solubility by showing above shown slide.

• The above shown graph is shown that connects the solubility and temperature of certain salts and activity card was given to each group and below mentioned points were discussed.
• Which substance shows maximum increase in solubility as temperature increases?
• Which salts have the same solubility at a temperature of 40°C?
• Which substance shows a decrease in solubility with increase in temperature?
• Students understood that, "The nature of solute and the temperature are two factors that influence solubility."

Classifications of Mixtures

• Class began with presenting the below shown slide and students were asked to compare these to examples and arrive at a conclusion.

• Students were shown the below shown slide and asks them to classify the items and they were explained on the concept of homogeneous mixtures with examples that if the composition of the constituents is the same throughout the mixture. 

                   

• Students understood by explanation that components of the heterogeneous mixtures can be seen.
• This subject was taught by concept attainment model.

This is all for the week. So far it has been so much that I have learned. Hopefully, Next Friday (29/11/2019) I will be sharing some more of my teaching experience. Good Bye.