Dear students, Your Class 8 Assignment Answer Science 2021 9th Week has been published. Then I will say that you have come to the website. In today’s article for you, there are two facts and experiments of diffusion and diffusion from daily observation.
Table of Contents
- 1 Lesson: From the daily observation, there are two cases of diffusion and diffusion
- 2 Class 8 Assignment Answer Science 2021 9th Week
- 3 Class 8 Assignment Answer Science 2021 9th Week
- 4 From the daily observation, there are two cases of diffusion and diffusion
Lesson: From the daily observation, there are two cases of diffusion and diffusion
Class 8 Assignment Answer Science 2021 9th Week
An assignment has been scheduled from the science textbook for eighth grade students with ninth week Bangla. This is the second science assignment of the students.
Eighth graders were given science first assignment atom structure, atomic number, mass number and isotope in the fourth week. Class 8 Assignment Answer Science 2021 9th Week.
In the ninth week, the third chapter of the science textbook: The second assignment has been given from Bipan, Abhisravana and Prasedvan. Students will complete this assignment after studying in the light of the ninth week short syllabus of eighth grade science subject prepared by the National Curriculum and Textbook Board. Class 8 Assignment Answer Science 2021 9th Week.
Class: VIII, Subject: Science, Assignment Number: 2
Class 8 Assignment Answer Science 2021 9th Week. Chapters and titles: III: diffusion, osmosis and perspiration; Lessons and Contents Included in the Curriculum: Lessons 1-2: Extension, Lesson-3: Absorption, Lesson 4: Importance of Absorption, Lesson 6: Perspiration, Lesson 6: Importance of Perspiration;
Assignment: Assign two incidents of diffusion and diffusion from your daily observations. Complete the test for any one of the diffusion and diffusion processes and write the whole process sequentially.
A. Properties of diffusion,
B. Features of osmosis,
C. Tests for diffusion and osmosis (observation of soaking in water, spreading of cooking odor, spreading of food coloring in water)
Instructions for writing assignments:
- This assignment has to be completed by linking the knowledge gained from Part 1 to 4 of the textbook to the environment.
- Collect and test the readily available materials.
- Keep in mind that the test is not risky.
Class 8 Assignment Answer Science 2021 9th Week
From the daily observation, there are two cases of diffusion and diffusion
Properties of diffusion
Class 8 Assignment Answer Science 2021 9th Week. The process by which the molecules of a liquid and gaseous substance spontaneously and uniformly disperse from a high density area to a low density area is called diffusion. That is, the spread continues until the density in the two areas is equal.
The kinetic energy of an atom of diffuse matter creates a kind of pressure called diffusion pressure.
- Diffusion is the movement of matter from one region to another.
- In this process it moves from high density region to low.
- It helps in the movement of useful molecules.
- The process of diffusion occurs in the physiological functions of the organism. For example, plants absorb carbon dioxide from the air during photosynthesis and release oxygen. This vital work is accomplished by diffusion.
From my daily observations, two incidents of diffusion are mentioned below:
- Scents or incense are spread all over the house. It is caused by diffusion. The molecules of incense smoke and scent are dispersed in low density areas throughout the room as they are highly concentrated. So all the houses are filled with fragrance.
- The spray of room freshener spreads in the air through which we can smell.
Class 8 Assignment Answer Science 2021 9th Week. Absorption is the physical process by which a solvent spreads from a low-density solution to a high-density solution when two different concentrations of the same substance and solvent are separated by a semipermeable membrane. If a solution with the same atmospheric pressure and heat level and its pure solvent can be separated by a heterogeneous, the amount of pressure required from the direction of the higher density solution to completely block the entry of the pure solvent into the denser solution by penetrating the heterogeneous membrane. Says osmotic pressure.
- In the process of osmosis, various mineral salts dissolved in water enter or exit the cell through the plasma membrane.
- Absorption plays a very important role in activating various biochemical processes in the cell.
- By this process the plant can absorb mineral salts dissolved in water and water from the soil.
- Helps to keep stems and leaves fresh and upright.
- Moreover, food can be absorbed in the intestines of animals.
From my daily observations, the following two incidents of osmosis are mentioned:
- As the water inside the raisins dries up, the raisins shrink. When raisins are put in water, they absorb water and swell. This is because the dark solution of sugar inside the raisins is separated from the water by a membrane. As a result, when water enters the raisins, the solvent water spreads from its low-density area to its high-density area, so the raisins swell.
- The wide mouth of a funnel is inserted into the fish fillet and placed in a solution of water. If the sugar solution is taken in the wide mouth of the funnel, the sugar solution will swell after a while. This means that osmosis is happening. Because in this case the crack acts as a semi-permeable screen. Then the water spreads from its low density area to its high density area. As a result the height of the sugar solution increases. Class 8 Assignment Answer Science 2021 9th Week.
A test of osmosis is mentioned below:
Work: Absorption test.
Ingredients: Thistle funnel, fish cracker, beaker, sugar solution, stand clamp.
Method: The wide mouth of thistle funnel should be covered with fish fillet and tied tightly with yarn and half water should be taken in the vicar. After taking water in the beaker, a thick solution of sugar should be poured through the tube of thistle funnel. Now the wide mouth of the funnel should be completely immersed in the water of the baker and the funnel should be attached to the stand with the help of clamp. Then mark the tube of the funnel with a marker pen and place the test system in a certain place. Class 8 Assignment Answer Science 2021 9th Week.
Observation: After a while, it can be seen that the solution of thistle funnel tube has risen upwards. After a while it was seen that it was not rising above the water.
Conclusion: From this it is understood that the process is absorption. Because the cracker acts as a semi-permeable membrane in this case, the water flows from its low-density area to its high-density area, thus increasing the height of the sugar solution.
So the process is osmosis. Class 8 Assignment Answer Science 2021 9th Week.
This was the Class 8 Assignment Answer Science 2021 9th Week – two incidents of diffusion and diffusion from daily observation.
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